Answer 1

you can use <iostream> and <conio.h> at some moment

look:

#include <iostream>
#include <conio.h>

using namespace std;

int x , y , sum;

int main()

{
cout << "first number: ";
cin >> x;

cout << "second number: ";
cin >> y;

sum = x + y;

cout << "sum:" <<sum;

return 0;

}