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())
lista = []
saida = []

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

for a in range(len(lista)):
    for b in range(len(lista)):
        if ((lista[a] * lista[b]  > x) & (lista[a] % lista[b]  == 0) & (lista[a]/lista[b] < x)):
            saida.append(lista[a])
            saida.append(lista[b])
            
if len(saida) == 0:
    print(-1)
else:
    print(saida[0], saida[1])