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#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
using namespace std;
const long long inf=1e18+7;
long long tab[210];
long long pref[210];
long long w[70][210][210];
long long wyn[70][210];
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	int n,i,j,k,l;
	long long pot,siz=0,m;
	cin>>n>>m;
	m++;
	for(i=1;i<=n;i++)
	{
		cin>>tab[i];
		pref[i]=pref[i-1]+tab[i];
	}
	for(i=1;i<=n;i++)
		w[0][i][i]=0;
	pot=2;
	for(k=1;pot<=m;k++,pot*=2)
	{
		for(i=1;i<=n;i++)
		{
			for(j=i;(j<=n)&&(j-i+1<=pot);j++)
			{
				w[k][i][j]=-inf;
				for(l=max((long long)i-1,(long long)j-(pot/2));l<=min((long long)j,(pot/2)+i-1);l++)
					w[k][i][j]=max(w[k][i][j],w[k-1][i][l]+w[k-1][l+1][j]+pref[j]-pref[l]);
				//cerr<<k<<" "<<i<<" "<<j<<" "<<w[k][i][j]<<"\n";
			}
		}
	}
	i=1;
	while(m>0)
	{
		while(pot>m)
		{
			pot/=2;
			k--;
		}
		for(j=1;j<=min((long long)n,siz+pot);j++)
		{
			wyn[i][j]=-inf;
			for(l=max(0LL,(long long)j-pot);l<=min((long long)j,siz);l++)
				wyn[i][j]=max(wyn[i][j],wyn[i-1][l]+w[k][l+1][j]+(pref[j]-pref[l])*(i-1));
			//cerr<<siz+pot<<" "<<j<<" "<<wyn[i][j]<<"\n";
		}
		m-=pot;
		siz+=pot;
		i++;
	}
	cout<<wyn[i-1][n]<<"\n";
	return 0;
}