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:
# https://codeforces.com/problemset/problem/1088/A

x, = map(int, input().split())

def find(x):
    for a in range(x,0,-1):
        for b in range(a, 0, -1):
            if a * b < x: break
            if a/b >= x: continue
            if a%b == 0: 
                return (a,b) # optimize here
    
    return (-1, '')

print("{} {}".format(*find(x)))