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:
n=input()
if n==1:
    print"-1"
else:
    flag=0
    for i in range(2,n+1):     #loop for b
        for j in range(i,n+1):    #loop for a
            if j%i==0 and i*j>n and j/i<n:
                print j,i
                flag=1
                break
        if flag==1:
            break
    if flag==0:
        print"-1"