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:
from bisect import bisect_right as br
from bisect import bisect_left as bl
from collections import defaultdict
from itertools import combinations
import sys
import math
MAX = sys.maxsize
MAXN = 10**5+10
MOD = 10**9+7
def isprime(n):
    n = abs(int(n))
    if n < 2:
        return False
    if n == 2: 
        return True    
    if not n & 1: 
        return False
    for x in range(3, int(n**0.5) + 1, 2):
        if n % x == 0:
            return False
    return True

def mhd(a,b,x,y):
    return abs(a-x)+abs(b-y)

def numIN():
    return(map(int,sys.stdin.readline().strip().split()))

def charIN():
    return(sys.stdin.readline().strip().split())

x = int(input())
if x==1:
	print(-1)
else:
	print(x,x)