プログラミングのテクニック/入力の処理(C,C++

#include(): Usage: (a-page-name-you-want-to-include[,title|,notitle])
#include(): Usage: (a-page-name-you-want-to-include[,title|,notitle])

using namespace std;

int main()
{

   double a;
   cin >> a;
   cout << a;
   return 0;

}