#include<iostream>
#include<algorithm>

int main() {
	int gx, gy, ex, ey;

	std::cin >> gx >> gy >> ex >> ey;

	int ans = 0;
	if (gx == gy && ex < gx && ey < gy && ex == ey)ans++;

	ans += std::max(gx, gy);
	std::cout << ans  << std::endl;
	return 0;

}