#include <iostream>
#include <vector>
using namespace std;

void findFarthestMisplaced(int N, vector<int>& A) {
    int max_so_far = A[0];
    int first = -1, last = -1;
    int first_max_index = 0;  // Track where the max_so_far first appeared

    for (int i = 1; i < N; i++) {
        if (A[i] < max_so_far) {
            if (first == -1) {
                first = first_max_index;  // The index where max_so_far first appeared
            }
            last = i;  // Update last misplaced index
        }

        // Update max_so_far and its index
        if (A[i] > max_so_far) {
            max_so_far = A[i];
            first_max_index = i;
        }
    }

    if (first == -1) {
        cout << "-1\n";
    } else {
        cout << first + 1 << " " << last + 1 << "\n";  // Convert to 1-based index
    }
}

int main() {
    int N;
    cin >> N;
    vector<int> A(N);

    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }

    findFarthestMisplaced(N, A);
    return 0;
}