#include <iostream>
int main()
{
std::cout << true << std::endl; // true evaluates to 1
std::cout << !true << std::endl; // !true evaluates to 0
bool b{false};
std::cout << b << std::endl; // b is false, which evaluates to 0
std::cout << !b << std::endl; // !b is true, which evaluates to 1
return 0;
}