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