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.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.InputMismatchException;
				
					 
					public class Solution1 implements Runnable
					{
						static final int MAX = 1000000007;
						static class InputReader
						{
							private InputStream stream;
							private byte[] buf = new byte[1024];
							private int curChar;
							private int numChars;
							private SpaceCharFilter filter;
							private BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
					
							public InputReader(InputStream stream)
							{
								this.stream = stream;
							}
							
							public int read()
							{
								if (numChars==-1) 
									throw new InputMismatchException();
								
								if (curChar >= numChars)
								{
									curChar = 0;
									try 
									{
										numChars = stream.read(buf);
									}
									catch (IOException e)
									{
										throw new InputMismatchException();
									}
									
									if(numChars <= 0)				
										return -1;
								}
								return buf[curChar++];
							}
						 
							public String nextLine()
							{
								String str = "";
					            try
					            {
					                str = br.readLine();
					            }
					            catch (IOException e)
					            {
					                e.printStackTrace();
					            }
					            return str;
							}
							public int nextInt()
							{
								int c = read();
								
								while(isSpaceChar(c)) 
									c = read();
								
								int sgn = 1;
								
								if (c == '-') 
								{
									sgn = -1;
									c = read();
								}
								
								int res = 0;
								do 
								{
									if(c<'0'||c>'9') 
										throw new InputMismatchException();
									res *= 10;
									res += c - '0';
									c = read();
								}
								while (!isSpaceChar(c)); 
								
								return res * sgn;
							}
							
							public long nextLong() 
							{
								int c = read();
								while (isSpaceChar(c))
									c = read();
								int sgn = 1;
								if (c == '-') 
								{
									sgn = -1;
									c = read();
								}
								long res = 0;
								
								do 
								{
									if (c < '0' || c > '9')
										throw new InputMismatchException();
									res *= 10;
									res += c - '0';
									c = read();
								}
								while (!isSpaceChar(c));
									return res * sgn;
							}
							
							public double nextDouble() 
							{
								int c = read();
								while (isSpaceChar(c))
									c = read();
								int sgn = 1;
								if (c == '-') 
								{
									sgn = -1;
									c = read();
								}
								double res = 0;
								while (!isSpaceChar(c) && c != '.') 
								{
									if (c == 'e' || c == 'E')
										return res * Math.pow(10, nextInt());
									if (c < '0' || c > '9')
										throw new InputMismatchException();
									res *= 10;
									res += c - '0';
									c = read();
								}
								if (c == '.') 
								{
									c = read();
									double m = 1;
									while (!isSpaceChar(c)) 
									{
										if (c == 'e' || c == 'E')
											return res * Math.pow(10, nextInt());
										if (c < '0' || c > '9')
											throw new InputMismatchException();
										m /= 10;
										res += (c - '0') * m;
										c = read();
									}
								}
								return res * sgn;
							}
							
							public String readString() 
							{
								int c = read();
								while (isSpaceChar(c))
									c = read();
								StringBuilder res = new StringBuilder();
								do 
								{
									res.appendCodePoint(c);
									c = read();
								} 
								while (!isSpaceChar(c));
								
								return res.toString();
							}
						 
							public boolean isSpaceChar(int c) 
							{
								if (filter != null)
									return filter.isSpaceChar(c);
								return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
							}
						 
							public String next() 
							{
								return readString();
							}
							
							public interface SpaceCharFilter 
							{
								public boolean isSpaceChar(int ch);
							}
						}
					 	
						public static void main(String args[]) throws Exception
						{
							new Thread(null, new Solution1(),"Solution1",1<<26).start();
						}
						long power(long x, long y)
						{
						    long res = 1;      // Initialize result
						 
						    x = x % MAX;  // Update x if it is more than or 
						                // equal to p
						 
						    while (y > 0)
						    {
						        // If y is odd, multiply x with result
						        if (y % 2 == 1)
						            res = (res*x) % MAX;
						 
						        // y must be even now
						        y = y>>1; // y = y/2
						        x = (x*x) % MAX;  
						    }
						    return res;
						}
						public void run()
						{
							InputReader sc= new InputReader(System.in);
							PrintWriter w= new PrintWriter(System.out);
							int a = sc.nextInt();
							int b= sc.nextInt();
							int c=  sc.nextInt();
							System.out.println(ans(a,b,c));
							w.close();
						}
						HashSet<Integer> hset = new HashSet();
						int ans(int a,int b,int c){
							int temp = -1;
							int count = 1;
							int z = 100000;
							while(z != 0){
								a = a* 10;
								temp = a/b;
								a = a % b;
								if(temp == c){
									return count;
								}else{
									count++;
								}
								z--;
							}
							return -1;
						}
						static class Pair implements Comparable<Pair>{
							int a;
							int b;
							Pair(int a,int b)	{
								this.a = a;
								this.b = b;
							}
							public boolean equals(Object o)
							{
								Pair p = (Pair)o;
								return p.a==a && p.b==b;
							}
							public int compareTo(Pair p){
								return Long.compare(this.a,p.a);
							}
							public int hashCode()
							{
								return new Long(a).hashCode()*31 + new Long(a).hashCode();
							}
						}
					}