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.util.HashSet;
import java.util.StringTokenizer;

/**
 * Created by dell on 12/11/2017.
 */
public class ques1 {
    static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
    public static void main(String args[])throws IOException
    {
        FastReader sc=new FastReader();
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int dividend=a;
        int cnt=1;
        HashSet<Integer> set=new HashSet<>();
        set.add(a);
        while(true){
            if(dividend<b)
            {
                dividend*=10;
            }
            if(set.contains(dividend))
            {
                System.out.println("-1");
                break;
            }
            set.add(dividend);
            int val=dividend/b;
            if(val==c)
            {
                System.out.println(cnt);
                break;
            }
            if(dividend%b==0){
                if(c==0)
                {
                    System.out.println(cnt+1);
                }
                else
                {
                    System.out.println("-1");
                }
                break;
            }
            dividend=dividend-b*val;
            cnt++;
        }
    }
}
