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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 10;
const long long int LINF = 1LL * INF * INF;
const int MAXN = 1e5 + 10;
const int MAXM = 3e3 + 10;
priority_queue<int> pq;
vector<vector<int> > graph;
int A[MAXN];
char S[MAXN];
int main() {
  int n, m, k, a, b, x, y;
  int sum = 0;
  int cnt = 0;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++)
      if (!(i % j)) {
        if (i * j > n && (i / j) < n) {
          printf("%d %d\n", i, j);
          return 0;
        }
      }
  printf("-1");
  return 0;
}