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:
#IN THE NAME OF GOD
'''
_=int(input())
for __ in range(2,_+1):
    ___=2
    while(True):
        ____=__*___
        if ____>_:
            break
        if __*____>_ and ____/__<_:
            print(____,__)
            exit()
        ___+=1
print(-1)'''
_=input()
print(-1 if _=="1" else _+" "+_)