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:

n=int(input())
f=0
for i in range(n//2,n+1):
	a=i
	for j in range(1,n+1):
		b=j
		if b==0 or a==0:
			break
		elif a%b==0 and a*b>n and a/b<n:
			print(a,b,sep=" ") 
			f=1
			break
		else:
			f=0	
	if f==1:
	 break		
if f==0:
	print('-1')