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())
flag=False
h=0
g=0
for k in range(1,x+1):
	for j in range(1,x+1):
		if (k%j)==0 and (k//j)<x and (j*k)>x:
			h=j
			g=k
			flag=True
			break
			break
if flag==True:
	print('{} {}'.format(g,h))
else:
	print("-1")