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. 

/**
 *
 * @author Zoro
 */
import java.util.Arrays;
import java.util.Collections;
import static java.util.Collections.reverse;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;
import java.util.Vector;
import static jdk.nashorn.internal.objects.NativeArray.sort;

/**
 *
 * @author Zoro
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner in = new Scanner(System.in);
        int a=in.nextInt(),b=in.nextInt(),c=in.nextInt(),pos=-1;
        for(int i=0;i<1000;++i){
            a*=10;
            if(a/b==c){
                pos=i+1;
                break;
            }else{
                a%=b;
            }
        }
        System.out.println(pos);
    }
}
