#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> p32;
typedef pair<ll, ll> p64;
typedef pair<double, double> pdd;
typedef vector<ll> v64;
typedef vector<int> v32;
typedef vector<vector<int>> vv32;
typedef vector<vector<ll>> vv64;
typedef vector<vector<p64>> vvp64;
typedef vector<p64> vp64;
typedef vector<p32> vp32;
ll MOD = 998244353;
double eps = 1e-12;
#define forn(i, e) for (ll i = 0; i < e; i++)
#define forsn(i, s, e) for (ll i = s; i < e; i++)
#define rforn(i, s) for (ll i = s; i >= 0; i--)
#define rforsn(i, s, e) for (ll i = s; i >= e; i--)
#define ln "\n"
#define dbg(x) cout << #x << " = " << x << ln
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define INF 2e18
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())

int main()
{
    // ifstream cin("be.txt");
    int n;
    cin >> n;

    vector<int> v(n + 1);
    for (int i = 1; i <= n; i++)
    {
        int a;
        cin >> a;
        v[a] = i;
    }

    int mini = v[n];
    int ans = 0;
    int ansK = n, ansV = n;
    for (int i = n - 1; i >= 1; i--)
    {
        int tav = v[i] - mini;
        if (v[i] > mini && tav > ans)
        {
            ans = tav;
            ansK = mini;
            ansV = v[i];
        }
        if (v[i] < mini)
        {
            mini = v[i];
        }
    }

    if (ans == 0)
        cout << -1;
    else
    {
        cout << ansK << " " << ansV;
    }

    return 0;
}