#include<iostream>
#include<algorithm>
using namespace std;
int main(void){
	int x, y, hx, hy; cin >> x >> y >> hx >> hy;
	int a = max(x, y);
	if (hx < x && hx == hy){
		cout << a + 1 << endl;
	}
	else cout << a << endl;
	return 0;
}