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

#define BYTE_LEN    8
#define NUM_BYTES   4
#define BYTE_MASK   0xFF

int byte_sum(uint32_t number);

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Usage: %s number\n", argv[0]);
    }

    uint32_t number = strtol(argv[1], NULL, 0);
    printf("%d\n", byte_sum(number));
}

// return the sum of the four bytes in number
int byte_sum(uint32_t number) {
    // TODO: complete this function
    return 0;
}