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:
import math
def check(a,b,x):
    if a > x or b > x:
        return False
    if a%b!=0:
        return False
    if a*b <= x:
        return False
    if a//b >= x:
        return False
    return True
limit = int(input())
value = math.ceil(math.sqrt(limit))
for k in range(1,value+1):
    multi = 1
    nxt = k*multi
    while nxt <= limit:
        if check(nxt,k,limit):
            print(nxt,k)
            exit()
        multi +=1
        nxt = k*multi
print (-1)