1110(더하기 사이클) 두번째 풀이

import sys
sys.stdin = open("input.txt","rt")

cnt = 0
a = sys.stdin.readline().strip()
b = a

if len(b) < 2:
    b = "0" + b

while True:

    if len(a) < 2:
        a = "0"+a

    plus_num = int(a[0]) + int(a[1])

    if len(str(plus_num)) > 1:
        plus_num = str(plus_num)[1]


    new_num = a[1] + str(plus_num)

    cnt += 1

    if new_num == b:
        break

    a = new_num

print(cnt)