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