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