diff --git a/18/Lab18/Lab18.cpp b/18/Lab18/Lab18.cpp
new file mode 100644
index 0000000..288bbf9
--- /dev/null
+++ b/18/Lab18/Lab18.cpp
@@ -0,0 +1,31 @@
+#include <iostream>
+#include <string>
+#include <ctype.h>
+#include <windows.h>
+
+using namespace std;
+
+// Тут не використано <string.h>, бо оновлена <ctype.h> прекрасно працює з цим
+int main() {
+
+    SetConsoleOutputCP(CP_UTF8);
+
+    string input;
+    cout << "Введіть строку: ";
+    getline(cin, input);
+
+    if (isupper(input[0])) {
+        for (int i = 0; i < input.length(); i++) {
+            input[i] = toupper(input[i]);
+        }
+    }
+    else {
+        for (int i = 0; i < input.length(); i++) {
+            input[i] = tolower(input[i]);
+        }
+    }
+
+    cout << "Result: " << input << endl;
+
+    return 0;
+}
diff --git a/18/Lab18/Lab18.sln b/18/Lab18/Lab18.sln
new file mode 100644
index 0000000..974650c
--- /dev/null
+++ b/18/Lab18/Lab18.sln
@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.3.32929.385
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Lab18", "Lab18.vcxproj", "{4CC4E666-A70B-4073-9409-7DDFED1903A8}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Debug|x64.ActiveCfg = Debug|x64
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Debug|x64.Build.0 = Debug|x64
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Debug|x86.ActiveCfg = Debug|Win32
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Debug|x86.Build.0 = Debug|Win32
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Release|x64.ActiveCfg = Release|x64
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Release|x64.Build.0 = Release|x64
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Release|x86.ActiveCfg = Release|Win32
+		{4CC4E666-A70B-4073-9409-7DDFED1903A8}.Release|x86.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {D7DCB7EE-8737-43FD-99BF-17DE8EBA19C2}
+	EndGlobalSection
+EndGlobal
diff --git a/18/Lab18/Lab18.vcxproj b/18/Lab18/Lab18.vcxproj
new file mode 100644
index 0000000..45dde3f
--- /dev/null
+++ b/18/Lab18/Lab18.vcxproj
@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <VCProjectVersion>16.0</VCProjectVersion>
+    <Keyword>Win32Proj</Keyword>
+    <ProjectGuid>{4cc4e666-a70b-4073-9409-7ddfed1903a8}</ProjectGuid>
+    <RootNamespace>Lab18</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0</WindowsTargetPlatformVersion>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="Shared">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <SDLCheck>true</SDLCheck>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ConformanceMode>true</ConformanceMode>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ConformanceMode>true</ConformanceMode>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <SDLCheck>true</SDLCheck>
+      <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ConformanceMode>true</ConformanceMode>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ConformanceMode>true</ConformanceMode>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="Lab18.cpp" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/18/Lab18/Lab18.vcxproj.filters b/18/Lab18/Lab18.vcxproj.filters
new file mode 100644
index 0000000..cb7bbd5
--- /dev/null
+++ b/18/Lab18/Lab18.vcxproj.filters
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="Source Files">
+      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
+      <Extensions>cpp;c;cc;cxx;c++;cppm;ixx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
+    </Filter>
+    <Filter Include="Header Files">
+      <UniqueIdentifier>{93995380-89BD-4b04-88EB-625FBE52EBFB}</UniqueIdentifier>
+      <Extensions>h;hh;hpp;hxx;h++;hm;inl;inc;ipp;xsd</Extensions>
+    </Filter>
+    <Filter Include="Resource Files">
+      <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
+      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="Lab18.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/18/Lab18/Lab18.vcxproj.user b/18/Lab18/Lab18.vcxproj.user
new file mode 100644
index 0000000..88a5509
--- /dev/null
+++ b/18/Lab18/Lab18.vcxproj.user
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="Current" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup />
+</Project>
\ No newline at end of file
diff --git a/18/Lab18/x64/Debug/Lab18.exe b/18/Lab18/x64/Debug/Lab18.exe
new file mode 100644
index 0000000..51d6710
Binary files /dev/null and b/18/Lab18/x64/Debug/Lab18.exe differ
diff --git a/18/Lab18/x64/Debug/Lab18.exe.recipe b/18/Lab18/x64/Debug/Lab18.exe.recipe
new file mode 100644
index 0000000..ec11508
--- /dev/null
+++ b/18/Lab18/x64/Debug/Lab18.exe.recipe
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+  <ProjectOutputs>
+    <ProjectOutput>
+      <FullPath>D:\2 семестр\Технології програмування\Lab18\x64\Debug\Lab18.exe</FullPath>
+    </ProjectOutput>
+  </ProjectOutputs>
+  <ContentFiles />
+  <SatelliteDlls />
+  <NonRecipeFileRefs />
+</Project>
\ No newline at end of file
diff --git a/18/Lab18/x64/Debug/Lab18.ilk b/18/Lab18/x64/Debug/Lab18.ilk
new file mode 100644
index 0000000..140bbf3
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diff --git a/18/Lab18/x64/Debug/Lab18.log b/18/Lab18/x64/Debug/Lab18.log
new file mode 100644
index 0000000..2ded9e1
--- /dev/null
+++ b/18/Lab18/x64/Debug/Lab18.log
@@ -0,0 +1,2 @@
+  Lab18.cpp
+  Lab18.vcxproj -> D:\2 семестр\Технології програмування\Lab18\x64\Debug\Lab18.exe
diff --git a/18/Lab18/x64/Debug/Lab18.obj b/18/Lab18/x64/Debug/Lab18.obj
new file mode 100644
index 0000000..ab7930a
Binary files /dev/null and b/18/Lab18/x64/Debug/Lab18.obj differ
diff --git a/18/Lab18/x64/Debug/Lab18.pdb b/18/Lab18/x64/Debug/Lab18.pdb
new file mode 100644
index 0000000..6a17582
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diff --git a/18/Lab18/x64/Debug/Lab18.tlog/CL.command.1.tlog b/18/Lab18/x64/Debug/Lab18.tlog/CL.command.1.tlog
new file mode 100644
index 0000000..e782643
Binary files /dev/null and b/18/Lab18/x64/Debug/Lab18.tlog/CL.command.1.tlog differ
diff --git a/18/Lab18/x64/Debug/Lab18.tlog/CL.read.1.tlog b/18/Lab18/x64/Debug/Lab18.tlog/CL.read.1.tlog
new file mode 100644
index 0000000..c56323f
Binary files /dev/null and b/18/Lab18/x64/Debug/Lab18.tlog/CL.read.1.tlog differ
diff --git a/18/Lab18/x64/Debug/Lab18.tlog/CL.write.1.tlog b/18/Lab18/x64/Debug/Lab18.tlog/CL.write.1.tlog
new file mode 100644
index 0000000..0313049
Binary files /dev/null and b/18/Lab18/x64/Debug/Lab18.tlog/CL.write.1.tlog differ
diff --git a/18/Lab18/x64/Debug/Lab18.tlog/Lab18.lastbuildstate b/18/Lab18/x64/Debug/Lab18.tlog/Lab18.lastbuildstate
new file mode 100644
index 0000000..abd5f8f
--- /dev/null
+++ b/18/Lab18/x64/Debug/Lab18.tlog/Lab18.lastbuildstate
@@ -0,0 +1,2 @@
+PlatformToolSet=v143:VCToolArchitecture=Native64Bit:VCToolsVersion=14.33.31629:TargetPlatformVersion=10.0.19041.0:
+Debug|x64|D:\2 семестр\Технології програмування\Lab18\|
diff --git a/18/Lab18/x64/Debug/Lab18.tlog/link.command.1.tlog b/18/Lab18/x64/Debug/Lab18.tlog/link.command.1.tlog
new file mode 100644
index 0000000..f6c85c8
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diff --git a/18/Lab18/x64/Debug/Lab18.tlog/link.read.1.tlog b/18/Lab18/x64/Debug/Lab18.tlog/link.read.1.tlog
new file mode 100644
index 0000000..5b705d2
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diff --git a/18/Lab18/x64/Debug/Lab18.tlog/link.write.1.tlog b/18/Lab18/x64/Debug/Lab18.tlog/link.write.1.tlog
new file mode 100644
index 0000000..68ba73a
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diff --git a/18/Lab18/x64/Debug/Lab18.vcxproj.FileListAbsolute.txt b/18/Lab18/x64/Debug/Lab18.vcxproj.FileListAbsolute.txt
new file mode 100644
index 0000000..f197960
--- /dev/null
+++ b/18/Lab18/x64/Debug/Lab18.vcxproj.FileListAbsolute.txt
@@ -0,0 +1 @@
+D:\2 семестр\Технології програмування\Lab18\x64\Debug\Lab18.exe
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