#include <stdio.h>
#include <stdint.h>
uint8_t extract_field(uint16_t reg) {
// Your logic here
uint16_t mask = (0x1f<<4);
//reg &= ~mask;
uint16_t field = (reg>>4)&0x1f;
return field;
}
int main() {
uint16_t reg;
scanf("%hx", ®);
printf("%u", extract_field(reg));
return 0;
}