#include <bits/stdc++.h>
using namespace std;
int a[2000001];
int main() {
  int n;
  cin >> n;
  int b[n];
  for (int i = 0; i < n; i++) {
    cin >> b[i];
    a[b[i]] = b[i];
  }
  sort(b, b + n);
  for (int i = 1; i <= 2 * b[n - 1]; i++) {
    if (a[i] == 0) a[i] = a[i - 1];
  }
  int mod = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (b[i] != b[i + 1] && mod < b[i])
      for (int j = 2 * b[i] - 1; j < 2000001, j <= 2 * b[n - 1]; j = j + b[i]) {
        int m = a[j] % b[i];
        if (mod < m) mod = m;
      }
  }
  cout << mod;
  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;
int a[2000001];
int main() {
  int n;
  cin >> n;
  int b[n];
  for (int i = 0; i < n; i++) {
    cin >> b[i];
    a[b[i]] = b[i];
  }
  sort(b, b + n);
  for (int i = 1; i <= 2 * b[n - 1]; i++) {
    if (a[i] == 0) a[i] = a[i - 1];
  }
  int mod = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (b[i] != b[i + 1] && mod < b[i])
      for (int j = 2 * b[i] - 1; j < 2000001, j <= 2 * b[n - 1]; j = j + b[i]) {
        int m = a[j] % b[i];
        if (mod < m) mod = m;
      }
  }
  cout << mod;
  return 0;
}

```