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())

a = 0
b = 0
for i in range(1,x+1):
  for j in range(1, x+1):
    if (i%j == 0) and (i*j > x) and (float(i)/float(j) < float(x)):
      a = i
      b = j

if (a == 0) and (b ==0):
  print(-1)
else:
  print(a, " ", b)