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:
'''input
3
'''
done = False
b = int(input())
for i in range(1,b+1):
	if (done):
		break
	for j in range(1,i+1):
		if (i%j==0 and (i*j>b) and (i/j<b)):
			print(i,j)
			done = True
			break
if (done==False):
	print(-1)