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:
# cook your dish here
s=int(input())
flag=0
for i in range(1,s+1):
    for j in range(1,s+1):
        a,b=i,j
        if a%b==0:
            if a*b > s:
                if (a/b) < s:
                    print(a,b)
                    flag=1
                    break
                else:
                    flag=0
            else:
                flag=0
        else:
            flag=0
    if flag==1:
        break
if flag==0:
    print(-1)