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())
resp = []
achou = False
for i in range(1,x+1):
	a = i
	for e in range(1, i+1):
		if a % e == 0 and a * e > x and a / e < x:
			resp.append(str(a))
			resp.append(str(e))
			achou = True
			break
	if achou:
		print(" ".join(resp))
		break
if not achou:
	print(-1)