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