#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define repr(i, n) for (int i = (n) - 1; i >= 0; i--)
#define range(a) a.begin(), a.end()

int main() {
  int a[4];
  rep(i, 4) cin >> a[i];
  int mn = INT_MAX;
  int mx = INT_MIN;
  rep(i, 4) {
    mn = min(mn, a[i]);
    mx = max(mx, a[i]);
  }
  set<int> st(a, a + 4);
  cout << (mx - mn == 3 && st.size() == 4 ? "Yes" : "No") << endl;
}