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