#include <bits/stdc++.h>
using namespace std;
vector<long long> dp;
vector<pair<int, int>> p;
int main() {
  int n;
  cin >> n;
  vector<int> a(n);
  map<int, int> m;
  dp = vector<long long>(n);
  for (size_t i = 0; i < n; i++) {
    cin >> a[i];
    m[a[i]]++;
  }
  for (auto element : m) {
    p.push_back(make_pair(element.first, element.second));
  }
  for (size_t i = 0; i < p.size(); i++) {
    int pr = i - 1;
    while (pr >= 0 && p[pr].first + 1 == p[i].first) pr--;
    if (pr == -1)
      dp[i] = 1LL * p[i].first * p[i].second;
    else
      dp[i] = dp[pr] + 1LL * p[i].first * p[i].second;
    if (i != 0) dp[i] = max(dp[i], dp[i - 1]);
  }
  cout << dp[(int)p.size() - 1];
  return 0;
}

### Prompt

Develop a solution in Cpp to the problem described below:

Alex doesn't like boredom. That's why whenever he gets bored, he comes up with games. One long winter evening he came up with a game and decided to play it.

Given a sequence a consisting of n integers. The player can make several steps. In a single step he can choose an element of the sequence (let's denote it ak) and delete it, at that all elements equal to ak + 1 and ak - 1 also must be deleted from the sequence. That step brings ak points to the player. 

Alex is a perfectionist, so he decided to get as many points as possible. Help him.

Input

The first line contains integer n (1 ≤ n ≤ 105) that shows how many numbers are in Alex's sequence. 

The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 105).

Output

Print a single integer — the maximum number of points that Alex can earn.

Examples

Input

2
1 2


Output

2


Input

3
1 2 3


Output

4


Input

9
1 2 1 3 2 2 2 2 3


Output

10

Note

Consider the third test example. At first step we need to choose any element equal to 2. After that step our sequence looks like this [2, 2, 2, 2]. Then we do 4 steps, on each step we choose any element equals to 2. In total we earn 10 points.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
vector<long long> dp;
vector<pair<int, int>> p;
int main() {
  int n;
  cin >> n;
  vector<int> a(n);
  map<int, int> m;
  dp = vector<long long>(n);
  for (size_t i = 0; i < n; i++) {
    cin >> a[i];
    m[a[i]]++;
  }
  for (auto element : m) {
    p.push_back(make_pair(element.first, element.second));
  }
  for (size_t i = 0; i < p.size(); i++) {
    int pr = i - 1;
    while (pr >= 0 && p[pr].first + 1 == p[i].first) pr--;
    if (pr == -1)
      dp[i] = 1LL * p[i].first * p[i].second;
    else
      dp[i] = dp[pr] + 1LL * p[i].first * p[i].second;
    if (i != 0) dp[i] = max(dp[i], dp[i - 1]);
  }
  cout << dp[(int)p.size() - 1];
  return 0;
}

```