#include <stdio.h>
#include <stdint.h>
uint8_t count_set_bits(uint8_t reg) {
// Your code here
if (reg == 0){
return 0;
}
char sbit=0x01;
char count=0;
for(char i=0;i<=7;i++){
if((reg>>i)&sbit==1){
count++;
}
else
continue;
}
return count;
}
int main() {
uint8_t reg;
scanf("%hhu", ®);
printf("%u", count_set_bits(reg));
return 0;
}