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 maxn = 100 + 10;
const double EPS = 1e-10;
const long long p = 1e7 + 9;
const long long mod = 1e9 + 7;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
inline int read() {
  int ret = 0, f = 0;
  char ch = getchar();
  while (ch > '9' || ch < '0') f ^= ch == '-', ch = getchar();
  while (ch <= '9' && ch >= '0') ret = ret * 10 + ch - '0', ch = getchar();
  return f ? -ret : ret;
}
int x;
int main() {
  ios::sync_with_stdio(false);
  cin >> x;
  int a, b;
  bool flag = false;
  for (int i = 1; i <= x; i++) {
    for (int j = 1; j <= x; j++) {
      if ((i % j == 0) && (i / j < x) && (i * j > x)) {
        flag = true;
        a = i;
        b = j;
        break;
      }
    }
  }
  if (flag) {
    cout << a << " " << b << endl;
  } else {
    cout << "-1" << endl;
  }
  return 0;
}