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