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:
x=int(input())
a=0
c=0
while (a<x) and (c<1):
    a+=1
    b=0
    while b<x:
        b+=1
        if (a%b==0) and (a*b>x) and (a/b<x):
            c=1
            print(a,b)
            break
if c==0:
    print(-1)