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())
a=1
b=1
while a<=n:
	if a*b>n and a//b<n and a%b==0:
		print(a,b)
		break
	else:
		b+=1
		a=b*2
if n!=1 and a>n:
	print(n,n)
elif a>n:
	print(-1)