Problem: Given an integer x, find 2 integers a and b such that: 

  * 1 ≤ a,b ≤ x 
  * b divides a (a is divisible by b). 
  * a ⋅ b>x. 
  * a/b<x. 

Input

The only line contains the integer x (1 ≤ x ≤ 100).

Output

You should output two integers a and b, satisfying the given conditions, separated by a space. If no pair of integers satisfy the conditions above, print "-1" (without quotes).

Examples

Input

10


Output

6 3

Input

1


Output

-1

Solution (in PYTHON3):

Solution:
x = int(input())
print('{} {}'.format(x, x)) if x > 1 else print('-1')
# pairs = []
# for b in range(x+1):
#     for a in range(b, x+1):
#         if a*b > x and a % b == 0 and a // b < x:
#             pairs.append((str(a), str(b)))
#
# if pairs:
#     print(' '.join(pairs[0]))
# else:
#     print('-1')