#include<iostream>
#include<string>

int main() {
	std::string weeks[2];

	std::cin >> weeks[0] >> weeks[1];

	int maxholidays = 0;
	int holidays = 0;
	for (int i = 0; i < 2; i++) {
		for (int j = 0; j < weeks[i].size(); j++) {
			if (weeks[i][j] == 'o') {
				holidays += 1;
			} else {
				if (maxholidays < holidays) {
					maxholidays = holidays;
				}
				holidays = 0;
			}
		}
	}
	if (maxholidays < holidays) {
		maxholidays = holidays;
	}
	std::cout << maxholidays << std::endl;
	return 0;
}