import java.util.Arrays;
import java.util.Scanner;
class M{
	static Scanner s=new Scanner(System.in);
	public static void main(String[]$){
		System.out.println(
				Arrays.stream((s.next()+s.next()).split("x"))
				.mapToInt(String::length)
				.max().orElse(0)
				);
	}
}