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())
for i in range(1,102):
	for j in range(1,102):
		y=int(i/j)
		if(i/j==y and i/j<x and i*j>x):
			print(i,j)
			break
	if(j<101):
		break
if(i==101 and j==101):
	print(-1)