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;
long double PI = acosl(-1);
bool compare_int(int a, int b) { return (a > b); }
bool compare_string(string a, string b) { return a.size() < b.size(); }
bool compare_pair(const pair<int, int> &a, const pair<int, int> &b) {
  if (a.second == b.second)
    return a.first < b.first;
  else
    return (a.second > b.second);
}
bool cmp(pair<string, int> x, pair<string, int> y) {
  return (x.second < y.second);
}
void NA() {
  printf("NO\n");
  exit(0);
}
void YA() {
  printf("YES\n");
  exit(0);
}
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int a, b, x;
  cin >> a >> b >> x;
  long long int cnt = -1;
  for (int i = 1; i <= 200005; i++) {
    a *= 10;
    if (a / b == x) {
      cnt = i;
      break;
    }
    a %= b;
  }
  cout << cnt << endl;
}
