#!/usr/bin/python

import sys

set_bits = 0

while True:
	block = sys.stdin.read(2**16)
	if not block:
		break
	#print('got block of length %d' % len(block))
	for char in block:
		byte = ord(char)
		#print('got char %d' % byte)
		for exponent in range(8):
			bitmask = 2**exponent
			#print('checking mask %d' % bitmask)
			if byte & bitmask != 0:
				#print('adding 1 to count')
				set_bits += 1

print(set_bits)