using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace YukiCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var s1 = Console.ReadLine();
            var s2 = Console.ReadLine();
            int max = (s1 + s2).Split('x').Select(v => v.Count()).Max();
            Console.WriteLine(max);
            Console.ReadLine();
        }
    }
}