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:
#In the name of GOD!

def chk(x):
	for a in range(x):
		for b in range(x):
			a = a + 1
			b = b + 1
			if a % b == 0 and a * b > x and a / b < x:
				print(str(a) + str(' ') + str(b))
				return True

x = int(input())
if not chk(x):
	print(-1)