Compile and Execute C++ Online

#include <iostream>

int main()
{
    // If you want to triple the number instead, you can change this to 3
    int multiplier = 2;
    std::cout << "Enter an integer:\n";
    int ;
    std::cin >> input;
    std::cout << "Double of that number (" << input << ") is " << input * multiplier << '\n';
    return 0;
}