"b" was not declared (Poczatkujacy :))

#include <iostream>
int main()
{
    int a = 1;
    do
    {
        std::cout << "podaj a" << std::endl;
        std::cin >> a;
        bool b = std::cin.good();
        std::cout << "good? " << b << std::endl;
    } while( b != 1 );
   
    return 0;
}