#include<bits/stdc++.h>

using namespace std;
using ll = long long;

int main(){
    int x,y,x1,y1;
    cin >> x >> y >> x1 >> y1;

    int ans = max(x,y);

    if(x == y && x1 < x && x1 == y1) ans++;

    cout << ans << endl;
    return 0;
}