#include <stdio.h>

int main( int argc, char* argv[] )
{
   char a = 20;		/* 00010100 = 16 + 4 = 20        */
   char b = 15;		/* 00001111 = 8 + 4 + 2 + 1 = 15 */
   
   printf( "a & b =  %d\n", (a & b) );
   printf( "a | b =  %d\n", (a | b) );
   printf( "a ^ b =  %d\n", (a ^ b) );
   printf( "~ a   =  %d\n", (~ a) );
}