#include <stdio.h>
#include <stdint.h>
#define BIT_POS 4
#define MASK 0x1F
uint8_t extract_field(uint16_t reg) {
// Your logic here
uint8_t value = 0;
value = (reg>>BIT_POS)&MASK;
return value;
}
int main() {
uint16_t reg;
scanf("%hx", ®);
printf("%u", extract_field(reg));
return 0;
}