#include <bits/stdc++.h>
using namespace std;
const int maxn = 2 * 1000000 + 10;
int adad[maxn], t, ans = 0;
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> t;
    adad[t] = t;
  }
  for (int i = 0; i <= maxn; i++)
    if (adad[i] == 0) adad[i] = adad[i - 1];
  for (int i = 2; i <= maxn; i++) {
    if (adad[i] == i) {
      for (int j = (2 * i) - 1; j <= maxn; j += i) ans = max(ans, adad[j] % i);
    }
  }
  cout << ans << endl;
  return 0;
}

### Prompt

Your task is to create a CPP solution to the following problem:

You are given a sequence a consisting of n integers. Find the maximum possible value of <image> (integer remainder of ai divided by aj), where 1 ≤ i, j ≤ n and ai ≥ aj.

Input

The first line contains integer n — the length of the sequence (1 ≤ n ≤ 2·105). 

The second line contains n space-separated integers ai (1 ≤ ai ≤ 106).

Output

Print the answer to the problem.

Examples

Input

3
3 4 5


Output

2

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
const int maxn = 2 * 1000000 + 10;
int adad[maxn], t, ans = 0;
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> t;
    adad[t] = t;
  }
  for (int i = 0; i <= maxn; i++)
    if (adad[i] == 0) adad[i] = adad[i - 1];
  for (int i = 2; i <= maxn; i++) {
    if (adad[i] == i) {
      for (int j = (2 * i) - 1; j <= maxn; j += i) ans = max(ans, adad[j] % i);
    }
  }
  cout << ans << endl;
  return 0;
}

```