#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int,int>;

int main(){
   int n, m;
   cin>>n>>m;
   vector<int> a(n);
   rep(i, n) cin>>a[i];

   sort(a.rbegin(), a.rend());

   m++;
   vector<int> dp(m), ndp(m);
   map<int, int> sp;
   sp[0]=INT_MIN/3;

   auto upd=[](int &a, int b){ a=max(a, b); };

   rep(i, n){
      {  
         rep(j, m) ndp[j]=dp[j];
         auto nt=sp.upper_bound(a[i]);
         auto it=nt; it--;
         rep(j, m){
            while(nt!=sp.end() && (nt->first)<=a[i]+j){
               it++; nt++;
            }
            upd(ndp[j], it->second);
         }
      }
      
      rep(j, m){
         int x=j+a[i], y=dp[j]+a[i];
         auto rt=sp.upper_bound(x);
         auto lt=rt; lt--;
         if((lt->second)>=y) continue;
         vector<map<int, int>::iterator> dl;
         for(; rt!=sp.end() && (rt->second)<=y; rt++){
            dl.push_back(rt);
         }
         for(auto it : dl) sp.erase(it);
         sp[x]=y;
      }
      swap(dp, ndp);
   }

   cout<<dp[m-1]<<endl;
   return 0;
}