#!/usr/bin/env python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


def to_int(word):
    L = len(word)
    if len(word) < 10000:
        return int(word)
    mid = L // 2
    n1 = to_int(word[:mid])
    n2 = to_int(word[mid:])
    return pow(10, L - mid) * n1 + n2


popcount = {hex(n)[2]: sum(map(int, bin(n)[2:])) for n in range(16)}
answer = sum(popcount[x] for x in hex(to_int(read().rstrip()))[2:])
print(answer)