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.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.StringTokenizer;

public class b {
	

	public static void main(String args[]) throws IOException {
		FastScanner in = new FastScanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		//BEGIN HERE

		int t = in.nextInt(), b = in.nextInt();
		int c = in.nextInt();
		
		BigDecimal bd = new BigDecimal(t);
		bd = bd.divide(BigDecimal.valueOf(b), 10000, RoundingMode.HALF_UP);
		
		String s = bd.toString();
		int ans = 0;
		for(int i = 2; i < s.length()-2; i++) 
			if(s.charAt(i) == (char)(c + '0')) {
				ans = i;
				break;
			}
		
		out.println(ans - 1);
		out.close();
	}

	static class FastScanner {
		BufferedReader br;
		StringTokenizer st;

		public FastScanner(InputStream i) {
			br = new BufferedReader(new InputStreamReader(i));
			st = null;
		}

		public String next() throws IOException {
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public String nextLine() throws IOException {
			if (st == null) {
				st = new StringTokenizer(br.readLine());
			}
			String line = st.nextToken("\n");
			st = null;
			return line;
		}

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

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

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