#include <bits/stdc++.h>
using namespace std;
const long long int N = 1e7 + 5;
long long int n, a[1000050], mx, ans = 1e17, x1, x2, in1, in2;
vector<long long int> d[N];
pair<long long int, long long int> solve() {
  cin >> n;
  for (long long int i = 1; i <= n; i++) {
    cin >> a[i];
    mx = max(mx, a[i]);
  }
  for (long long int i = 1; i <= n; i++) {
    if (d[a[i]].size() > 1) continue;
    d[a[i]].push_back(a[i]);
  }
  for (long long int i = 1; i <= mx; i++) {
    for (long long int j = i + i; j <= mx; j += i) {
      if (d[i].size() > 1) break;
      for (long long int k : d[j]) {
        if (d[i].size() > 1) break;
        d[i].push_back(k);
      }
    }
  }
  for (long long int i = 1; i <= mx; i++) {
    if (d[i].size() <= 1) continue;
    long long int temp = (d[i][0] * d[i][1]) / i;
    if (temp < ans) {
      ans = temp;
      x1 = d[i][0];
      x2 = d[i][1];
    }
  }
  for (long long int i = 1; i <= n; i++) {
    if (a[i] == x1 && (!in1))
      in1 = i;
    else if (a[i] == x2)
      in2 = i;
  }
  if (in1 > in2) swap(in1, in2);
  return {in1, in2};
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  pair<long long int, long long int> P = solve();
  cout << P.first << " " << P.second;
  return 0;
}
