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())
a=1
b=1
flag=True
while(a%b!=0 or (a/b)>=n or (a*b)<=n):
    if a<=n:
        a+=1
    if b<=n:
        b+=1
    if(a>n and b>n):
        print(-1)
        flag=False
        break;

if(flag):
    print(a,b)