#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
bool et[N];
int n;
int mob[N];
vector<int> d[N];
int cnt[N];
bool get(int x) {
  int coprime = 0;
  for (auto p : d[x]) coprime += cnt[p] * mob[p];
  return coprime > 0;
}
void update(int x, int val) {
  for (auto p : d[x]) cnt[p] += val;
}
int main() {
  for (int i = 1; i < N; i++) {
    for (int j = i; j < N; j += i) d[j].push_back(i);
    if (i == 1)
      mob[i] = 1;
    else if ((i / d[i][1]) % d[i][1] == 0)
      mob[i] = 0;
    else
      mob[i] = -mob[i / d[i][1]];
  }
  cin >> n;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    et[x] = 1;
  }
  for (int i = 1; i < N; i++) {
    for (auto x : d[i])
      if (i != x) et[x] |= et[i];
  }
  long long ans = 0;
  stack<int> s;
  for (int i = N - 1; i >= 1; i--) {
    if (et[i] == 0) continue;
    while (get(i) > 0) {
      ans = max(ans, 1LL * i * s.top());
      update(s.top(), -1);
      s.pop();
    }
    update(i, 1);
    s.push(i);
  }
  cout << ans;
}
