package main

import "fmt"

func main () {
	// 入力
	var week1, week2 string

	fmt.Scan(&week1)
	fmt.Scan(&week2)

	weeks := week1 + week2

	max, cnt := 0, 0

	for i := 0; i < len(weeks); i++ {
		if weeks[i:i+1] == "x" {
			if max < cnt {
				max = cnt
			}
			cnt = 0
		} else {
			cnt++
		}
	}
	if max < cnt {
		max = cnt
	}
	fmt.Println(max)
}