def find_misplaced_elements(nums, n):
max_length = 0
first_num = 0
second_num = 0
minimums = [0] * n
# minimums[-i] megmondja a leghatso i minimumat
minimums[-1] = nums[-1]
for i in range(n - 2, -1, -1):
minimums[i] = min(minimums[i + 1], nums[i])
for i in range(n - 1):
# if minimums[i+1] >= nums[i]:
# continue
if minimums[-1] < nums[i]:
if n - 1 - i > max_length:
max_length = n - 1 - i
first_num = i
second_num = n - 1
continue
lo = max_length + i + 1
if lo > n - 1:
break
hi = n - 1
if minimums[lo] >= nums[i]:
continue
while hi - lo > 1:
mid = (lo + hi) // 2
if minimums[mid] < nums[i]:
lo = mid
else:
hi = mid
max_length = lo - i
first_num = i
second_num = lo
if max_length > 0:
print(first_num + 1, second_num + 1)
else:
print(-1)
#n = int(input())
#nums = tuple(map(int, input().split()))
#n = len(nums)
import bisect
def find_misplaced_elements_2(nums, n):
max_length = 0
first_num = 0
second_num = 0
minimums = [0]*n
# minimums[-i] megmondja a leghatso i minimumat
minimums[-1]=nums[-1]
for i in range(n-2,-1, -1):
minimums[i] = min(minimums[i+1],nums[i])
for i in range(n-1):
#if minimums[i+1] >= nums[i]:
# continue
if minimums[-1] < nums[i]:
if n-1-i > max_length:
max_length = n-1-i
first_num = i
second_num = n-1
continue
lo=max_length+i+1
if lo>n-1:
break
hi=bisect.bisect(minimums,nums[i])
#print(minimums)
#print(nums[i],hi)
if hi-i-1 > max_length:
max_length = hi-i-1
first_num = i
second_num = hi-1
if max_length > 0:
print(first_num+1, second_num+1)
else:
print(-1)
n = int(input())
nums = list(map(int, input().split()))
n = len(nums)
#print(n)
find_misplaced_elements_2(nums, n)