Having watched the last Harry Potter film, little Gerald also decided to practice magic. He found in his father's magical book a spell that turns any number in the sum of its digits. At the moment Gerald learned that, he came across a number *n*. How many times can Gerald put a spell on it until the number becomes one-digit?
The first line contains the only integer *n* (0 ≤ *n* ≤ 10<sup class="upper-index">100000</sup>). It is guaranteed that *n* doesn't contain any leading zeroes.
0
0
10
1
991
3
99
2
100
1
123456789
2
32
1
86
2
2
0
8
0
34
1
13
1
28
2
23
1
57
2
29
2
353869285
3
549548646
2
858893424
2
644818852
3
360322525
3
122937520
2
288403032
2
677257481
3
58059561
3
211288847
2
339900034079539584
2
784084029310269952
3
774730557264864000
3
478233807148352256
3
165646874056812544
3
477533739511673792
3
660119944377002240
3
448375218506078080
3
77213334785795616
3
165767221702271872
3
1
0
5
0
8
0
156161456146164104103460452045416165146141414651641564105461465156445621465146514562146145465165145145614561465145614561
3
9
0
from sys import stdin,stdout
from heapq import heapify,heappush,heappop,heappushpop
from collections import defaultdict as dd, deque as dq,Counter as C
from bisect import bisect_left as bl ,bisect_right as br
from itertools import combinations as cmb,permutations as pmb
from math import factorial as f ,ceil,gcd,sqrt,log,inf
mi = lambda : map(int,input().split())
ii = lambda: int(input())
li = lambda : list(map(int,input().split()))
mati = lambda  r : [ li() for _ in range(r)]
lcm = lambda a,b : (a*b)//gcd(a,b) 
MOD=10**9+7
def soe(n):
    prime = [True for i in range(n+1)]
    p = 2
    while (p * p <= n):
        if (prime[p] == True):
            for i in range(p * p, n+1, p):
                prime[i] = False
        p += 1
    return(prime)
def ncr(n,r):
    p,k=1,1
    if (n - r < r):
        r = n - r
    if r!=0:
        while(r):
            p,k=p*n,k*r
            m=gcd(p,k)
            p,k=p//m,k//m
            n,r=n-1,r-1
    else:
            p=1
    return(p)




def solve():
    n=input()
    ans=0
    while(len(n)>1):
        temp=0
        for x in range(len(n)):
            temp+=ord(n[x])-ord("0")
        n=str(temp)
        ans+=1
    print(ans)
for _ in range(1):
    solve()