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;
int dr[] = {1, 1, 0, -1, -1, -1, 0, 1};
int dc[] = {0, 1, 1, 1, -1, -1, -1, -1};
int R, C;
int grid[100][100];
int floodfill(int r, int c, char c1, char c2) {
  if (r < 0 || r >= R || c < 0 || c >= C) return 0;
  if (grid[r][c] != c1) return 0;
  int ans = 1;
  grid[r][c] = c2;
  for (int i = 2; i < 8; i++) {
    ans += floodfill(r + dr[i], c + dc[i], c1, c2);
  }
  return ans;
}
int main() {
  int x, a, b;
  cin >> x;
  for (int i = x - 1; i > 1; i--) {
    for (int j = 2; j < x; j++) {
      if (i % j == 0 && i * j > x && (i / j) < x) {
        printf("%d %d\n", i, j);
        return 0;
      }
    }
  }
  if (x != 1)
    printf("%d %d\n", x, x);
  else
    puts("-1");
  return 0;
}