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:
rr = raw_input
N = int(rr())


def solve(N):
    for a in xrange(1, N+1):
        for b in xrange(1, N+1):
            if a % b == 0 and a*b > N and a < N*b:
                return [a,b]
    return [-1]

print " ".join(map(str, solve(N)))