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.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.*;
import java.io.IOException;
import java.io.InputStream;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class Main {
    public static void main(String[] args) {

        File file = new File("in.txt");
        File fileOut = new File("out.txt");
        InputStream inputStream = null;
        OutputStream outputStream = null;
        // try {inputStream= new FileInputStream(file);} catch (FileNotFoundException ex){return;};
//        try {outputStream= new FileOutputStream(fileOut);} catch (FileNotFoundException ex){return;};
        inputStream = System.in;
        outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }


}

class Task {

    public void solve(int testNumber, InputReader in, PrintWriter out) {

        Integer a = in.nextInt();
        Integer b = in.nextInt();
        Integer c = in.nextInt();

        boolean[] seen = new boolean[b+1];
        Integer seenCount = 0;


        Integer rem = a;
        Integer pos =0;
        while(seenCount<=b){
            rem = rem * 10;
            Integer output = rem / b;
            rem = rem % b;
            pos++;

            if(output.equals(c)){
                out.println(pos);
                return;
            }

            if(!seen[rem]){
                seen[rem] = true;
                seenCount++;
            }
            else{
                break;
            }

        }
        out.println(-1);
    }










}


class InputReader {
    public BufferedReader reader;
    public StringTokenizer tokenizer;

    public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream), 32768);
        tokenizer = null;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine(){
        try {
            return reader.readLine();
        } catch (IOException e){
            throw new RuntimeException(e);
        }
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }
    public long nextLong() { return Long.parseLong(next()); }

}



class Pair<F, S> {
    public final F first;
    public final S second;




    public Pair(F first, S second) {
        this.first = first;
        this.second = second;
    }

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof Pair)) {
            return false;
        }
        Pair<?, ?> p = (Pair<?, ?>) o;
        return Objects.equals(p.first, first) && Objects.equals(p.second, second);
    }

    @Override
    public int hashCode() {
        return (first == null ? 0 : first.hashCode()) ^ (second == null ? 0 : second.hashCode());
    }

    @Override
    public String toString() {
        return "(" + first + ", " + second + ')';
    }
}

class IntPair extends Pair<Integer, Integer>{
    public IntPair(Integer first, Integer second){
        super(first, second);
    }
}