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:
#!/usr/bin/env python3
import sys

def rint():
    return map(int, sys.stdin.readline().split())
#lines = stdin.readlines()

x = int(input())

for b in range(1, x+1):
    for a in range(b, x+1):
        if a%b == 0 and a*b > x and a < b*x:
            print(a, b)
            exit()

print(-1)