#include <iostream>
#include <cmath>

void foo(double x, double y)
{
    double cx = cos(x);
    double cy = cos(y);
    std::cout << cx << std::endl;
    if (cx != cy) 
        std::cout << "Я знаю точно невозможное возможно";
}

int main()
{
    foo(1.0, 1.0);
    return 0;
}