#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

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