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

int main() {
    int a,b,c,d;
    cin>>a>>b>>c>>d;
    if (a==b&&c==d&&c<a) {
        cout<<a+1<<endl;
    } else {
        cout<<max(a,b)<<endl;
    }
    return 0;
}