#include<bits/stdc++.h>
#define int int64_t

using namespace std;

bool sorted(int a[], int sz){
    for(int i = 1; i <= sz; i++)
        if(a[i] != i)
            return false;
    return true;
}

int32_t main(){
    int n;
    cin >> n;
    int h[n + 1];
    for(int i = 1; i <= n; i++)
        cin >> h[i];
    if(sorted(h, n)) {
        cout << "-1 -1";
        return 0;
    }
    pair<int, int> ans = {1, 2};
    int dlt = abs(h[ans.first] - ans.first) + abs(h[ans.second] - ans.second) - abs(h[ans.first] - ans.second) - abs(h[ans.second] - ans.first);
    for(int i = 1; i <= n; i++)
        for(int j = i + 1; j <= n; j++)
            if(dlt < abs(h[i] - i) + abs(h[j] - j) - abs(h[i] - j) - abs(h[j] - i))
                ans = {i, j}, dlt = abs(h[i] - i) + abs(h[j] - j) - abs(h[i] - j) - abs(h[j] - i);
    cout << ans.first << ' ' << ans.second;
}