Visal C++ program

#include <iostream>
#include <stdio.h>

int main()
{
   system("color fc");
  std::cout << "Ahoj Pcforum!\n";
  std::cout << "Press Enter to Exit\n";
  while ( getchar() != '\n' );
  return 0;

}

std::cout << "Ahoj Pcforum!\n";
  std::cout << "Press Enter to Exit\n";

std::cout << "Ahoj Pcforum!" << std::endl << "Press Enter to Exit" << std::endl;

#include <iostream>
#include <stdio.h>

int main()
{
   system("color fc");
  std::cout << "Ahoj Pcforum!\n";
  std::cout << "\n";
  std::cout << "\n";
  std::cout << "\n";
  std::cout << "\n";
  std::cout << "\n";
  std::cout << "Press Enter to Exit\n";
  while ( getchar() != '\n' );
  return 0;

}

std::cout << "\n\n\n\n\n";

for(int i=0;i<5;i++);
std::cout<<std::endl;

while ( getchar() != '\n' );

std::cin.get();

#include <iostream>

int main() {
    system("color f0");
   std::cout << "Ahoj Pcforum!\n";
   std::cout << "\n\n";
   std::cout << "Press Enter to Exit!" << std::endl;
   std::cin.get();
    return 0;
}

for(int i=0;i<5;i++)
std::cout<<std::endl;

private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
      List<String^> gcnew List<String^>();
             Sentences->Add("sgjghkardgtfhkertjujj");
             Sentences->Add("sfdjsfhjhgj");
             Sentences->Add("dfjdghjdhgjhgj");
             Sentences->Add("fguhjdgfjd");
             Random^ rand = gcnew Random();
             int r = rand->Next(Sentences->Count);
             textBox1->Text = Sentences[r];

using namespace System::Collections::Generic;

error C2147: syntax error : 'gcnew' is a new keyword
error C2065: 'Sentences' : undeclared identifier