def binary_search(nums, target, left, right):
    while left <= right:
        mid = (left + right) // 2
        if nums[mid] == target:
            return mid
        elif nums[mid] < target:
            left = mid + 1
        else:
            right = mid - 1
    return -1

def find_misplaced_elements(nums):
    n = len(nums)
    max_index = 0
    min_index = n - 1

    for i in range(1, n):
        if nums[i] < nums[i - 1]:
            max_index = i - 1
            break

    for i in range(n - 2, -1, -1):
        if nums[i] > nums[i + 1]:
            min_index = i + 1
            break

    if max_index == 0 and min_index == n - 1:
        return -1

    correct_max_index = binary_search(nums, nums[max_index], min_index, n - 1)

    correct_min_index = binary_search(nums, nums[min_index], 0, max_index)

    return max_index, correct_min_index if correct_min_index != -1 else min_index

# Read input
n = int(input())
nums = list(map(int, input().split()))

# Find the indices of the misplaced elements
result = find_misplaced_elements(nums)

# Print the result
if result == -1:
    print(-1)
else:
    print(result[0], result[1])