#include <stdio.h>
#include <stdint.h>
uint8_t extract_field(uint16_t reg) {
uint16_t mask;
uint8_t res;
mask= (0x1F)<<4;
res= (reg & mask)>>4;
return res;
}
int main() {
uint16_t reg;
scanf("%hx", ®);
printf("%u", extract_field(reg));
return 0;
}