#include <iostream>
#include <stdlib.h>
#include <limits.h>

int main( void )
{
        long long num;
        std::cout << "Enter a positive or negative number: ";
        if ( ! ( std::cin >> num ) ) {
                std::cerr << "Unable to read a number; giving up\n";
                exit( 1 );
        }
        std::cout << num << " == " << std::hex << std::showbase << num << '\n';
        std::cout << std::dec << num << " (dec) = ";
        for ( unsigned i = 0; i < sizeof( long long ) * CHAR_BIT; ++i ) {
                if ( num < 0 )
                        std::cout << 1;
                else
                        std::cout << 0;
                num <<= 1;
        }
        std::cout << " (bin) \n";
        return 0;
}