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
import sys,math
'''
n,w = map(int,input().split())
f=[[-1 for i in range(w+2)] for x in range(n+2)]
f[0][0]=0
weight=[]
value=[]
for _ in range(n):
    W,V = map(int,input().split())
    weight.append(W)
    value.append(V)
def opt(weight,value,n,w):
    if n>=0 and f[n][w]<0:
        if w<weight[n]:
            return opt(weight,value,n-1,w)
        else:
            val =\
            max(opt(weight,value,n-1,w),value[n]+opt(weight,value,n-1,w-weight[n]))
        f[n][w] = val
    return f[n][w]
print(opt(weight,value,n-1,w))

n = int(input())
a = list(map(int,input().split()))
f=[0]*(n+1)
f[0] = min(abs(a[0]-1),abs(a[0]+1))
temp = pow(10,16)
for i in range(1,n):
    f[i] = min(abs(a[i]+1),abs(a[i]-1))+f[i-1]
print(f)
'''
def how(n,c):
    if n<=9:
        return c
    else:
        s=0
        while n!=0:
            s+=n%10
            n=n//10
        return how(s,c+1)
t  = int(input())
print(how(t,0))



























