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 PYTHON):

Solution:
x = input()
ans = []
for a in range(1, x+1):
	for b in range(1, x+1):
		if a%b == 0:
			if a*b > x:
				if float(a)/b < x:
					ans = [a,b]
					break
if ans:
	print " ".join(map(str, ans))
else:
	print -1