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

#define _p(...) (void)printf(__VA_ARGS__)
#define forr(x,arr) for(auto&& x:arr)
#define rep(i,a,b) for (int i = (a); i < (b); i++)
#define rrep(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define ALL(x) (x).begin(), (x).end()
#define BIT(n) (1LL<<(n))
#define SZ(x) ((int)(x).size())
#define fst first
#define snd second
#define dump( x ) cerr << #x << " = " << ( x ) << endl
typedef long long ll;
// -------------------------------------

void Main() {
  int x, y, x2, y2;
  scanf("%d%d", &x, &y);
  scanf("%d%d", &x2, &y2);

  int ans;
  if (x != y) {
    ans = max(x, y);
  }
  else {
    ans = x + (x2 == y2 && x2 < x);
  }

  _p("%d\n", ans);
}
int main() { cin.tie(0); ios::sync_with_stdio(false); Main(); return 0; }