17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

#define Extract_Nibble(x,pos) (x >> (pos * 4)) & 0x000f

unsigned char extractNibble(unsigned char reg, int pos) 
{
    return Extract_Nibble(reg, pos);
}

int main() {
    unsigned char reg;
    int pos;
    scanf("%hhu %d", &reg, &pos);
    printf("%d", extractNibble(reg, pos));
    return 0;
}