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:
#!/usr/bin/env python
# coding: utf-8

# In[1]:


import math


# In[12]:


n=int(input())


# In[ ]:


#n, m=list(map(int, input().rstrip().split()))
#data=[]
#for i in range(0,n):
#    data.append( list(map(int, input().rstrip().split())))


# In[13]:


#answer=-1

#for i in range(1,n+1):
 #   a=i
  #  for j in range(1,a):
   #     b=j    
    #    if a % b ==0:
     #       if a*b>n:
      #          if a//b<n:
       #             answer=str(a)+ " "+str(b)


# In[14]:


if n==1:
    print(-1)
else:
    print( str(n)+' '+str(n))


# In[ ]: