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