#include <bits/stdc++.h>
using namespace std;

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);

	int x, y; cin >> x >> y;
	int x2, y2; cin >> x2 >> y2;
	if(x == y && x2 == y2 && x2 < x && y2 < y) cout << max(x, y) + 1 << endl;
	else cout << max(x, y) << endl;
	
	return 0;	
}