#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>

using namespace std;

int main() {
	int x, y, x2, y2;

	cin >> x >> y >> x2 >> y2;

	int ans = max(x, y);
	if (x == y && x2 == y2 && x2 < x) {
		ans ++;
	}
	cout << ans << endl;
	return 0;
}