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:
def getnums(x):
    for b in range(2,x+1):
        for a in range(x,0,-1):
            #print(a,b)
            if (a*b)>x and a<(b*x) and a%b==0:
                return a,b
    return -1,-1


x=int(input())
a,b=getnums(x)
if a==-1:
    print("-1")
else:
    print("{} {}".format(a,b))