using System;
using System.Linq;

class LargestCommonEnd
{
    static void Main(string[] args)
    {
        string[] arr = Console.ReadLine()
            .Split(new char[] { ' ' },
                StringSplitOptions.
                    RemoveEmptyEntries);
        string[] arr2 = Console.ReadLine()
            .Split(new char[] { ' ' },
                StringSplitOptions.
                    RemoveEmptyEntries);
        int LeftCount = CommonMaxEnd(arr, arr2);
        Array.Reverse(arr);
        arr2 = arr2.Reverse().ToArray();
        int RightCount = CommonMaxEnd(arr, arr2);
        Console.WriteLine($"{Math.Max(LeftCount, RightCount)}");

    }
    private static int CommonMaxEnd(string[] arr, string[] arr2)
    {
        int Similar = Math.Min(arr.Length, arr2.Length);
        int count = 0;
        for (int i = 0; i < Similar; i++)
        {
            if (arr[i] == arr2[i])
            {
                count++;
            }
            else
            {
                break;
            }
        }
        return count;

    }
}