#include <stdio.h>
#include <stdint.h>
uint8_t count_set_bits(uint8_t reg) {
// Your code here
int cnt=0;
for(int bit=7;bit>=0;bit--){
if((reg>>bit)&1 == 1){
cnt++;
}
}
return cnt;
}
int main() {
uint8_t reg;
scanf("%hhu", ®);
printf("%u", count_set_bits(reg));
return 0;
}