#include <iostream>
#include <vector>

using namespace std;

int main()
{
	int n;
	cin >> n;
	vector<int> v(n);

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

	vector<int> c(n);
	c[0] = v[0];
	for (int i = 1; i < n; i++)
	{
		c[i] = max(c[i - 1], v[i]);
	}

	int maxim = -1, start, end;

	for (int i = 0; i < n; i++)
	{
		int mIndex = lower_bound(c.begin(), c.end(), v[i]) - c.begin();
		if (i - mIndex > maxim && i - mIndex != 0)
		{
			maxim = i - mIndex;
			end = i + 1;
			start = mIndex + 1;
		}
	}

	if (maxim == -1)
	{
		cout << -1;
	}
	else
	{
		cout << start << " " << end << endl;
	}
}