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:
n=int(input())
for i in range(1,101):
    a=i
    j=1
    while j<=i:
        b=j
        if a*b>n and a//b<n and a%b==0:
            print(a,end=" ")
            print(b)
            exit()
        j+=1
print("-1")