#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>

static const int MOD = 1000000007;
using ll = int64_t;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

int main() {
    int x, y, a, b;
    cin >> x >> y >> a >> b;
    if(x == y && a == b && x > a){
        cout << x+1 << "\n";
    }else {
        cout << max(x, y) << "\n";
    }
    return 0;
}