Вопрос Ошибка при создании программы на С++ помоги найти ошибку

#include
#include
#include

using std:: cout;
using std:: cin;
using std:: endl;

int mail()
{
setlocale(LC_ALL,"Russian");

int a,b;

a = 24;
b = 12;

cout << " a = " << a << " b = " << b << endl;
cout << " a + b = " << (a+b) << endl;
cout << " a - b = " << (a-b) << endl;
cout << " a / b = " << (a/b) << endl;
cout << " a * b = " << (a*b) << endl;

_getch();
return 0;
}