text: #include <iostream>
  #include <string>
  #include <vector>
  #include <algorithm>
  #include <utility>
  #include <tuple>
  #include <cstdint>
  #include <cstdio>
  #include <map>
  #include <queue>
  #include <set>
  #include <stack>
  #include <deque>
  #include <unordered_map>
  #include <unordered_set>
  #include <bitset>
  #include <cctype>
  
  using namespace std;
  
  typedef long long    ll;
  typedef long double  ld;
  typedef pair<ll, ll> pll;
  typedef pair<ld, ld> pld;
  
  #define rep(i, n)      for (int i = 0; i < (int)(n); ++i)
  #define rep3(i, m, n)  for (int i = (m); i < (int)(n); ++i)
  #define rrep(i, n)     for (int i = (int)(n)-1; i >= 0; --i)
  #define rrep3(i, m, n) for (int i = (int)(n)-1; i >= (m); --i)
  #define all(x) begin(x), end(x)
  #define rall(x) end(x), begin(x)
  #define mset(x, val) memset(x,(val),sizeof(x))
  #define cons(a, b) make_pair((a), (b))
  #define car first
  #define cdr second
  
  #define endl '\n'
  const ll   INF  = 0x7f7f7f7f7f7f7f7f;
  const int  INFi = 0x7f7f7f7f;
  const string YES = "YES";
  const string NO = "NO";
  
  ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
  
  bool solve(int n, const vector<int64_t> & a) {
    // TODO: edit here
  }
  
  int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
  
    // failed to analyze input format
    // TODO: edit here
    int n;
    cin >> n;
    vector<ll> a(n);
    rep (i, n) {
      cin >> a[i];
    }
  
    auto ans = solve(n, a);
    cout << (ans ? YES : NO) << endl;
  
    return 0;
  }
  