#include <iostream>
using namespace std;

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