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

int main(){
	long long x,y;
	cin >> x >> y;
	long long x2,y2;
	cin >> x2 >> y2;
	long long ans;
	if(x != y) ans = max(x,y);
	else if(x2 < x and x2 == y2) ans = x + 1;
	else ans = x;
	cout << ans << endl;
	return 0;
}