#include <stdio.h>
#include <stdint.h>
uint8_t extract_field(uint16_t reg) {
// Your logic here
// uint8_t field = uint8_t ( (reg & 0x01F0) >> 4);
return uint8_t ( (reg & 0x01F0) >> 4);
}
int main() {
uint16_t reg;
scanf("%hx", ®);
printf("%u", extract_field(reg));
return 0;
}