<?php
$week1 = str_split(trim(fgets(STDIN)));
$week2 = str_split(trim(fgets(STDIN)));
$week = array_merge($week1, $week2);
// もしも丸がつづいたらかうんとする
$count = $ans = 0;
foreach ($week as $key => $value){
    if ($week[$key] === "o"){
        $count ++;
        } else {
            $ans = max($count, $ans);
            $count = 0;
    }
}
echo max($ans, $cnt);