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.*;
import java.io.*;
import java.math.*;
import java.util.StringTokenizer;
 
public class decimalvalue{
    public static void main(String[] args){
        FastReader scan=new FastReader();
        PrintStream p = System.out;
        double a = scan.nextDouble();
        double b = scan.nextDouble();
        String c = scan.next();
        BigDecimal d1 =  new BigDecimal(a);
        BigDecimal d2 =  new BigDecimal(b);
        BigDecimal d3 =  d1.divide(d2,256,RoundingMode.DOWN);
        String s = d3.toString();
        String s1 = "";
        int len = 0,count=0;
        
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)=='.'){
                s1 += s.substring((i+1),s.length());
                break;
            }
        }
        //p.println(s1);
        for(int i=0;i<s1.length();i++){
            count++;
            if(s1.charAt(i)==c.charAt(0)){
                p.println(count);
                return;
            }
            
        }
        
        p.println("-1");
    }
    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;
        }
    }
}

