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())
q = None
r = None
for b in range(2, x+1):
	for a in range(b, x+1, b):	
		if a*b > x and a//b < x:
			q = a
			r = b
			break
	if q and r:
		break

if q and r:
	print(q, r)
else:
	print(-1)