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. 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.Scanner;


public class Main {

    private static int[] recursiveSearch(int[] a, int[] choosenNumbers, int sumA, int sumB) {
        int[] retArr = null;
        /*for (int i = 0; i < choosenNumbers.length; i++) {

        }*/
        return retArr;
    }

    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(System.in);
        String[] arr;
        int[] resultArr;
        int a, x, y, b, c, k, n, paper, rounds, maxNum, p, countStrings = 0;
        a = in.nextInt();
        b = in.nextInt();
        c = in.nextInt();
        p = 0;
        while (true) {
            if (a < b) {
                a *= 10;
                if (c == 0 && a < b) {
                    System.out.println(p + 1);
                    return;
                }
                p++;
            } else {
                k = a % b;
                n = (int) Math.floor(a / b);
                a = k;
                if (n == c) {
                    System.out.println(p);
                    return;
                }
                if (k == 0) {
                    if (c == 0) {
                        System.out.println(p + 1);
                    } else {
                        System.out.println(-1);
                    }
                    return;
                }
                if (p > 1000000) {
                    System.out.println(-1);
                    return;
                }
            }
        }

    }

}