#include <iostream>
#include <cstdio>
using namespace std;

int main() {
int n,x=0,y=0;
int t=0,cnt=0;
scanf_s("%d", &n);
if (n < 0 || n>99) {
return 0;
}
int result = n;

while ((y * 10 + (t % 10)) != result) {

x = n / 10;
y = n % 10;
t = x + y;
n = y * 10 + (t % 10);
cnt++;
}

cout << cnt << endl;
return 0;
}

뭐가 문제일까요...ㅠㅠ