import java.util.*;
public class Main {
public static void main (String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
int n = sc.nextInt();
int[] nums = new int[n];
for (int i = 0; i < n; i++) {
nums[i] = sc.nextInt();
}
int[] res = getRange(n, nums);
System.out.println(res[0] + " " + res[1]);
}
}
public static int[] getRange (int n, int[] nums) {
int[] res = new int[2];
res[0] = res[1] = -1;
if (n <= 2 || nums.length != n) {
return res;
}
LinkedList<Integer> result = new LinkedList<Integer>();
int i = 1;
if (nums[i] > nums[i -1 ]) {
result.add(i - 1);
}
while (i < n - 1) {
if (nums[i - 1] > nums[i] && nums[i] < nums[i + 1]) {
result.add(i);
}
i++;
}
if (nums[n - 1] < nums[n - 2]) {
result.add(n - 1);
}
int maxW = 0;
int left = 0;
int right = 0;
while (result.size() > 1) {
left = result.getFirst();
result.removeFirst();
right = result.getFirst();
if (maxW < right - left) {
res[0] = left;
res[1] = right;
maxW = right - left;
}
}
return res;
}
}