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