using System;

public class Program

{

    public static void Main()

    {

for(int i=1;i<=10;i++)

{

int n=int.Parse(Console.ReadLine());

int digit=int.Parse(Console.ReadLine());

Console.WriteLine(lastindex( n,digit));

​

}   

}   

public static int lastindex(int n,int digit)

{

int c=0,a=0;        

while(n!=0)

{

c++;

if(digit==n%10)

a=c;

n/=10;

}   

if(a==0)

return -1; 

else 

return a;   

}

}