using System;

class Program
{
    static void Main()
    {
        string[] firstArray = Console.ReadLine().Split();
        string[] secondArray = Console.ReadLine().Split();

        int counter1 = 0;
        int counter2 = 0;

        for (int i = 0; i < Math.Min(firstArray.Length, secondArray.Length); i++)
        {
            if (firstArray[i] == secondArray[i])
            {
                counter1++;
            }
            else
            {
                break;
            }
        }

        for (int i = Math.Min(firstArray.Length, secondArray.Length) - 1; i >= 0; i--)
        {
            int arrayDiff = Math.Abs(firstArray.Length - secondArray.Length);
            try
            {
                if (secondArray[i] == (firstArray[i + arrayDiff]))
                {
                    counter2++;
                }
                else
                {
                    break;
                }
            }
            catch (Exception)
            {

                break;
            }

        }

        if (!(counter1 == 0 && counter2 == 0))
        {
            Console.WriteLine(Math.Max(counter1, counter2));
        }
        else
        {
            Console.WriteLine(0);
        }

    }
}