#include <bits/stdc++.h>
using namespace std;
template<class T>bool chmax(T& xx, T yy) { if (xx < yy) { xx = yy; return true; }return false; }

int main() {
    int N, M, ans = 0;
    cin >> N >> M;
    vector<int>numbers(N);
    vector<pair<int, int>>pairs(N - 1);
    vector<vector<int>>dp(N + 1, vector<int>(M + 1, 0));
    dp[0][0] = 0;
    for (int i = 0; i < N; i++)cin >> numbers[i];
    sort(numbers.begin(), numbers.end());
    reverse(numbers.begin(), numbers.end());
    for (int i = 0; i < N - 1; i++) {
        pairs[i].first = numbers[i] - numbers[i + 1];
        pairs[i].second = numbers[i];
    }
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < M + 1; j++) {
            if (i < N - 1 && j + pairs[i].first <= M) {
                dp[i + 2][j + pairs[i].first] = dp[i][j] + pairs[i].second;
            }
            chmax(dp[i + 1][j], dp[i][j]);
        }
    }
    for(int i=0; i < M + 1; i++) chmax(ans, dp[N][i]);
    cout << ans << endl;
}