27. Extract Bit Field from 16-bit Register

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

#define WIDTH (5)
#define POS (4)
#define MASK ((1u<<WIDTH)-1)
uint8_t extract_field(uint16_t reg) {
    uint8_t field = (reg >> POS) & MASK;

    return field;
}

int main() {
    uint16_t reg;
    scanf("%hx", &reg);
    printf("%u", extract_field(reg));
    return 0;
}