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:
from sys import stdin, stdout
from math import *
from heapq import *
from collections import *

def main():
    x=int(stdin.readline())
    for a in range(1,x+1):
        for b in range(a,x+1):
            if (a%b==0):
                if  (((a*b)>x)and((a/b)<x)):
                    stdout.write(" ".join([str(a),str(b)]))
                    return 0
    stdout.write("-1")
    return 0

if __name__ == "__main__":
    main()