#include <iostream>

int main( void )
{
        int num;

        for (;;)       /* or while ( 1 ) */
        {
                std::cout << "Please enter a number: ";
                if ( ! ( std::cin >> num ) )
                        break;
                int square = num * num;
                std::cout << "Square of " << num
                     << " = " << square << '\n';
                char ch;
                std::cout << "Another square? (y/n) ";
                if ( std::cin >> ch && ch != 'y' )
                        break;
        }
}