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