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:
num = int(input())
lista = []
resultado = []

for i in range(num):
	lista.append(i+1)

for a in (lista):
	for b in (lista):
		if((a <= num) & (b <= num) & (a % b == 0) & (a * b > num) & (a / b < num)):
			resultado.append(a)
			resultado.append(b)

if(len(resultado) == 0):
	print(-1)
else:
	print(resultado[0],resultado[1])