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

void findFarthestMisplaced(int N, vector<int>& A) {
    int min_right = A[N - 1];  // Rightmost element
    int first = -1, last = -1;

    // Traverse from right to left
    for (int i = N - 2; i >= 0; i--) {
        if (A[i] > min_right) {
            first = i;  // Update first occurrence
            if (last == -1) last = i + 1;  // First misplaced pair
        }
        min_right = min(min_right, A[i]);  // Update min from right
    }

    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;
}