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:
# n, m = map(int, input().split())
# a = []
# b = []
# c = []
# for i in range(n):
#     a.append([int(x) for x in input().split()])
# for i in range(n):
#     z = [int(x) for x in input().split()]
#     b.append(z)
#     k = []
#     for j in range(m):
#         if z[j] - a[i][j] < 0:
#             print(-1)
#             exit()
#         k.append(z[j] - a[i][j])
#     c.append(k)
# ans = []
# for i in range(n):
#     r = min(a[i])
#     ans.append(('R', i, r))
#     for j in range(m):
#         a[i][j] += r
# print(a)
# # print(ans)
# for i in range(m):
#     l = []
#     t = 0
#     for j in range(n):
#         if a[j][i] == b[j][i]:
#             t = 1
#
#         l.append(a[j][i])
#     if t == 1:
#         continue
#     z = min(l)
#     # ans.append(('C', i, z))
#     for j in range(n):
#         a[j][i] += z
# print(a)
# print(b)
# if a != b:
#     print(-1)
#     exit()
# print(ans)
# #
# # for i in range(n):
# #     for j in range(m):
# #         r = b[i]
# #         l = []
# #         pi = []
# #         for zp in range(n):
# #             l.append(zp)
# #             pi.append(b[zp][j])
# #         if 0 not in r:
# #             zk = min(r)
# #             for op in range(m):
# #                 b[i][op] -= zk
# #             ans.append(('R', i, zk))
# #         if b[i][j] != 0:
# #             if 0 not in pi:
# #                 zk = min(pi)
# #                 for op in range(n):
# #                     b[l[op]][j] -= zk
# #                 ans.append(('C', j, zk))
# #             if l[i] != 0:
# #                 print(-1)
# #                 exit()
# # print(len(ans))
# # for i in ans:
# #     print(i[0], i[1] + 1, i[2])
x = int(input())
for i in range(1, x + 1):
    for j in range(1, x + 1):
        if (i * j > x) and (i / j < x) and (j % i == 0 and i % j == 0):
            print(j, i)
            exit()
print(-1)