Baekjoon 1110번(python)

N = input()

if(int(N) < 10):
    N = '0' + N

check_value = int(N)
count = 0
while True:
    add_value = int(N[0]) + int(N[1])
    count += 1
    
    N = N[-1] + str(add_value)[-1] 
    if(check_value == int(N)):
        break
print(count)