(unsigned long)-1 (unsigned long)~0

#include <stdio.h>
#include <stdlib.h>


int main (int argc, char **argv){

    printf("0x%lx\n", (unsigned long) -1);
    printf("0x%lx\n", (unsigned long) ~0);

    return 0;
}

/*
 output:

 0xffffffffffffffff
 0xffffffffffffffff

 */