import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No0203 {
	public static boolean flg = false;

	public static void main(String[] args){
		try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))){
			char c1[] = br.readLine().toCharArray();
			char c2[] = br.readLine().toCharArray();
			int cnt = 0;
			int ans = Counter(c2, Counter(c1, cnt));
			System.out.println(ans);

		}catch(IOException e){
			e.printStackTrace();
		}
	}

	public static int Counter(char c[], int cnt){
		int ans = 0;
		if(flg){
			ans = cnt;
		}
		for(int i=0; i<c.length; i++){
			if(c[i] == 'o'){
				ans++;
				cnt = Math.max(cnt, ans);
				flg = true;
			}else{
				flg = false;
				ans = 0;
			}

		}
		return cnt;
	}
}