17. Extract the Nibble from an 8-bit Register

#include <stdio.h>
#define Upper_Nibble_Mask 0xF0
#define Lower_Nibble_Mask 0x0F
unsigned char extractNibble(unsigned char reg, int pos) 
{
    // Write your code here
    if(pos == 0)
    {
        reg = reg & Lower_Nibble_Mask;
    }
    else
    {
        reg = ((reg & Upper_Nibble_Mask) >> 4);

    } 
    return reg;
}

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