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:
""" 

"""

import sys
import bisect
import heapq
import math
from Queue import *
from collections import *

sys.setrecursionlimit(10**9+7)

def fi():
    return int(sys.stdin.readline())
def fi2():
    return map(int, sys.stdin.readline().split())
def fi3():
    return sys.stdin.readline().rstrip()
def fo(*args):
    for s in args:
        sys.stdout.write(str(s)+' ')
    sys.stdout.write('\n')
##    sys.stdout.flush()
def puts(*args):
    for s in args:
        sys.stdout.write(str(s))

##
OUT = []
def bfo(*args):
    for s in args:
        OUT.append(str(s)+' ')
    OUT.append('\n')
def bputs(*args):
    for s in args:
        OUT.append(str(s))        
def flush():
    sto = ''.join(OUT)
    fo(sto)
##

alpha = 'abcdefghijklmnopqrstuvwxyz'
N = 101010
mod = 10**9+7
inf = 10**18+5

##

        



##
#main

x = fi()

if x == 1:
    bfo(-1)

else:
    bfo(x, x)





flush()