#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>
#include <queue>
#include <stack>

using namespace std;


int main()
{
		
	long long x,y,x2,y2;
	cin>>x>>y>>x2>>y2;
	
	long long res=max(x,y);
	
	if(x==y && x2==y2 && x2<x) res++;

	cout<<res<<endl;
	

	return 0;
}