#include <bits/stdc++.h>

using namespace std;

const int maxn = 1000010;

bitset<maxn * 10> v, v1;

int a[maxn];

vector<int> ans;

long long res = 1e18;

int main() {

	int n, res1, res2, pos1 = -1, pos2 = -1, mx = 0;

	scanf("%d", &n);

	for (int i = 1; i <= n; i++) {

		scanf("%d", &a[i]);

		mx = max(mx, a[i]);

		if(v[a[i]] == 1) v1[a[i]] = 1;

		v[a[i]] = 1;

	}

	for (int i = 1; i <= mx; i++) {

		ans.clear();

		for (int j = i; j <= mx; j += i) {

			if(v[j]) {

				ans.push_back(j);

				if(v1[j]) ans.push_back(j);

				if(ans.size() >= 2) break;

			}

		}

		if(ans.size() < 2) continue;

		if(res > (long long)ans[0] * ans[1] / i) {

			res = (long long)ans[0] * ans[1] / i;

			res1 = ans[0], res2 = ans[1];

		}

	}

	int flag = 0;

	for (int i = 1; i <= n; i++) {

		if(pos1 == -1 && res1 == a[i]) {

			pos1 = i;

			flag |= 1;

			continue;

		}

		if(pos2 == -1 && res2 == a[i]) {

			pos2 = i;

			flag |= 2;

		}

		if(flag == 3) break;

	}

	if(pos1 > pos2) swap(pos1, pos2);

	printf("%d %d\n", pos1, pos2);

}