#include <stdio.h>
#include <stdint.h>
uint8_t count_set_bits(uint8_t reg) {
// Your code here
uint8_t cnt = 0;
for(uint8_t i = 0;i < 8;i++){
if((reg >> i) & 1)cnt++;
}
return cnt;
}
int main() {
uint8_t reg;
scanf("%hhu", ®);
printf("%u", count_set_bits(reg));
return 0;
}