#include <iostream>

std::string x[] = {"X", "O", "X", "O"};

int main()
{
    std::cout << "Before: " << x[0] + x[1] + x[2] + x[3] << std::endl;
    for (int i = 0; i < 4; i++)
    {
        x[i] = std::to_string(i);
    }
    std::cout << "after: " << x[0] + x[1] + x[2] + x[3] << std::endl;
 return 0;
}