#include <iostream>
int main( void )
{
        double fahr, cel;
        std::cout << "Enter fahrenheight: ";
        if ( ! ( std::cin >> fahr ) )
                return 1;
        cel = ( 5.0 / 9.0 ) * ( fahr - 32 );
        std::cout << fahr << " deg F => "
             << cel << " deg C\n";
}