Using the IO library, we can extend our main program to prompt the user to give us two numbers and then print their sum

#include <iostream>
int main()
{
std::cout << "Enter two numbers:" << std::endl;
int v1 = 0, v2 = 0;
std::cin >> v1 >> v2;
std::cout << "The sum of " << v1 << " and " << v2
<< " is " << v1 + v2 << std::endl;
return 0;
}

Output:

Enter two numbers:
3 7
The sum of 3 and 7 is 10