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.math.BigDecimal;
import java.math.RoundingMode;
import java.util.*;
public class Main {

	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		
		/*
		int scale =100;
		BigDecimal num1 = new BigDecimal(a);
		BigDecimal num2 = new BigDecimal(b);
		
		
		String s = num1.divide(num2,scale,RoundingMode.HALF_UP).toString();
		
		s = s.substring(0, 20);
		//System.out.println(s);
		int n = s.length();
		
		boolean flag = false;
		boolean found = false;
		
		int count =0;
		for (int i =0;i<n;i++)
		{
			if (s.charAt(i)=='.')
			{
				flag = true;
				
				continue;
			}
			if (flag)
			{
				char ch = (char)(c+48);
				
				if (s.charAt(i)==ch)
				{
					
					count++;
					found = true;
					break;
				}
				count++;
			}
			
		}
		if (c==0 && !found)
		{
			System.out.println(count+1);
		}
		else if (!found)
			System.out.println(-1);
		else
		System.out.println(count);
		
		*/
		
		int num =0,prev =0;
		int i =0;
		a = a%b;
		a = a*10;
		boolean flag = false;
		while(i<10000)
		{
			num = a/b;
			a=a%b;
			a*=10;
			prev++;
			if (num==c)
			{
				System.out.println(prev);
				flag = true;
				break;
			}
			i++;
		}
		if (!flag)
			System.out.println(-1);
		
		
		sc.close();

	}

}
