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:
# A. Ehab and another construction problem


# x_list = range(1, 101)
#
# for i in range(x_list):

x = int(input())

def correct(a, b):
    good = True
    if (1 > a or a > x) and (1 > b or b > x):
        good = False
    if a % b != 0:
        good = False
    if a * b <= x:
        good = False
    if a / b >= x:
        good = False
    return good

correct_list = []
for i in range(1, x+1):
    for j in range(1, x+1):
        if correct(i, j):
            correct_list.append((i, j))
if correct_list:
    print(correct_list[0][0], correct_list[0][1])
else:
    print(-1)