You have a fraction <image>. You need to find the first occurrence of digit c into decimal notation of the fraction after decimal point.

Input

The first contains three single positive integers a, b, c (1 ≤ a < b ≤ 105, 0 ≤ c ≤ 9).

Output

Print position of the first occurrence of digit c into the fraction. Positions are numbered from 1 after decimal point. It there is no such position, print -1.

Examples

Input

1 2 0


Output

2

Input

2 3 7


Output

-1

Note

The fraction in the first example has the following decimal notation: <image>. The first zero stands on second position.

The fraction in the second example has the following decimal notation: <image>. There is no digit 7 in decimal notation of the fraction. 
#include <bits/stdc++.h>
using namespace std;
const double EPS = 1e-9;
const double pi = acos(-1);
const long long int INF = 1e18;
const int inf = 1e9;
const int MOD = 1e9 + 7;
const int nax = 300000 + 10;
int n, arr[nax], q;
int bucketno[nax], localpos[nax], en[nax];
const int rtn = 1000;
int mat[rtn + 1][rtn + 1], dp[rtn + 1][rtn + 1];
unordered_map<int, int> cnt[rtn + 1];
void compute(int bucket) {
  cnt[bucket].clear();
  dp[bucket][0] = mat[bucket][0];
  for (int i = 1; i <= en[bucket]; i++) {
    dp[bucket][i] = dp[bucket][i - 1] ^ mat[bucket][i];
  }
  for (int i = 0; i <= en[bucket]; i++) cnt[bucket][dp[bucket][i]]++;
}
int main() {
  ios::sync_with_stdio(0);
  long long int a, b, c;
  map<int, int> map1;
  cin >> a >> b >> c;
  a = a % b;
  for (int i = 1; i <= 100000; i++) {
    a *= 10;
    if (a / b == c) {
      cout << i;
      return 0;
    }
    a %= b;
  }
  cout << -1;
  return 0;
}
