#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
int main() {
  int n;
  cin >> n;
  vector<long long> a(n);
  for (int i = 0; i < (n); ++i) {
    cin >> a[i];
  }
  if (n == 3)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
