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 PYTHON):

Solution:
n = int(raw_input())
a=b=-1
for i in xrange(2,n+1):
    for j in xrange(i,n+1):
        if i*j>n and j%i==0 and j/i<n:
            a,b=j,i
            break
if a>-1 and b>-1:
    print a, b
else:
    print -1