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:
x = int(raw_input())
##def isprime(n):
##    for i in range(2,int(n**0.5)+1):
##        if n % i == 0:
##            return False
##            break
##    else:
##        return True
if x == 1:
    print -1
##elif isprime(x):
##    print x,x
else:
    print x,x