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 long int power(long long int x, long long int y) {
  if (y == 0)
    return 1;
  else if (y % 2 == 0)
    return power(x, y / 2) * power(x, y / 2);
  else
    return x * power(x, y / 2) * power(x, y / 2);
}
long long int binsearch(long long int a[], long long int n, long long int x) {
  long long int low = 1;
  long long int high = n;
  long long int ans;
  while (low <= high) {
    long long int mid = (low + high) / 2;
    if (a[mid] == x)
      return mid;
    else if (a[mid] > x) {
      ans = mid;
      high = mid - 1;
    } else {
      low = mid + 1;
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int a, b, c;
  cin >> a >> b >> c;
  long long int pos = -1;
  for (long long int i = 1; i < 100005; i++) {
    a *= 10;
    if (a / b == c) {
      pos = i;
      break;
    }
    a = a % b;
  }
  cout << pos << endl;
}
