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:
import sys

x = int(input())
f = True

for i in range(1,x+1):
    for j in range(1,x+1):
        if((i*j>x) and (i%j==0) and (float(i/j)<float(x)) and f):
            print(i,j)
            f = False
            sys.exit(0)

if(f):
    print("-1")