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 int mod = 1e9 + 7;
const int MAXN = 3e5 + 10;
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  assert(b >= 0);
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long gcd(long long a, long long b) {
  long long c;
  while (a != 0) {
    c = a;
    a = b % a;
    b = c;
  }
  return b;
};
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
int used[1010110];
int main() {
  int x, y, c, q, res, ok = 0;
  cin >> x >> y >> c;
  x = x * 10;
  for (int i = 1;; ++i) {
    res = x / y;
    q = x % y;
    if (used[x]) {
      cout << -1 << endl;
      break;
    }
    if (res == c) {
      cout << i << endl;
      ok = 1;
      break;
    }
    used[x] = 1;
    x = q * 10;
  }
}
