/*#include <iostream> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#include <unordered_map> // unordered_map
#include <unordered_set> // unordered_set
#include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
#include <iomanip>//fixed,setprecision
#include <limits.n>//INT_MAX
#include <math.n>//M_PI
#include <random>
#include <regex> // 正規表現
#include <time.h>*/
#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
//using mint = modint998244353;
//std::chrono::time_point<std::chrono::steady_clock> start;
template <typename T> bool chmax(T &u, const T z) { if (u < z) {u = z; return true;} else return false; }
template <typename T> bool chmin(T &u, const T z) { if (u > z) {u = z; return true;} else return false; }
#define ll long long
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
typedef pair<int, int> P;
ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
ll lcm(ll a, ll b){return a * b / gcd(a, b);}

struct Student {
  int sum,no, sugaku, eigo;

  // 演算子オーバーロードで比較関数を定義
  bool operator<(const Student& another) const {
    if(sum!=another.sum)return sum>another.sum;
    if (sugaku != another.sugaku)
      return sugaku > another.sugaku; // 高い順に並べたいので演算子を逆に
    if (eigo != another.eigo)
      return eigo > another.eigo; // 同様に比較演算子を反転
    return no < another.no;
  }
};

const int mod=1000000007;
struct combination {
  vector<mint> fact, ifact;
  combination(int n):fact(n+1),ifact(n+1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n]*ifact[k]*ifact[n-k];
  }
}c(555);

int main(){
  int n;
  cin>>n;
  vector<ll>a(n);
  rep(i,n)cin>>a[i];
  sort(a.begin(),a.end());
  if(n==1||n==4)cout<<a[0]<<endl;
  else if(n==2)cout<<a[0]*a[1]<<endl;
  else cout<<1<<endl;
  return 0;
}