using System;

public class Program

{

    public static int fun1(String a , String b){

        return a.IndexOf(b); // already implemented method that can be used  

    }

    public static int fun2(String a, String b){

        int i=0,j=0;

        int idx = -1;

        while (i<a.Length && j < b.Length){

            if (a[i] == b[j]){

                if (j == 0 )

                    idx = i;

                j++;

            }

            else

                j=0;

            i++;

        }

        if (j != b.Length)

            idx = -1;

        return idx;

    }

    public static void Main()

    {

        String a,b;

        a = Console.ReadLine();

        b = Console.ReadLine();

        Console.WriteLine(fun2(a,b));

    }

}