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:
x = int(raw_input())
def solve(x):
    for b in xrange(1, x + 1):
        for a in xrange(1, x + 1):
            ok = True
            if not (a % b == 0): ok =  False
            if not (a * b > x): ok = False
            if not (a / b < x): ok = False
            if ok:
                return a, b
    return -1
got = solve(x)
print got if type(got) is int else "{} {}".format(got[0], got[1])