# your code goes here
def lidi(li):
    A=[]
    i=0
    if li[0]==1:
        li[1]+=10
        i+=1
    while i<len(li)-1:
        if li[i]%2==1:
            li[i+1]+=10
        A.append(li[i]//2)
        i+=1
    A.append(li[i]//2)
    return A
N=input()
Nl=list(N)
Ni=[0]*len(Nl)
for i in range (len(Nl)):
    Ni[i]=int(Nl[i])
Od=0
while len(Ni)>1:
  #  print(Ni)
    if Ni[len(Ni)-1]%2==1:
        Od+=1
    Ni=lidi (Ni)
M=Ni[0]
while M>1:
    if M%2==1:
        Od+=1
    M//=2
print (Od+1)