#include <stdio.h>
#include <stdint.h>
uint8_t extract_field(uint16_t reg) {
// Your logic here
uint8_t res = 0;
uint16_t mask = ((1U<<5)-1)<<4;
reg = ((reg & mask)>>4);
res = res | reg;
return res;
}
int main() {
uint16_t reg;
scanf("%hx", ®);
printf("%u", extract_field(reg));
return 0;
}