#include <fstream>
#define nmax 34570
#define inf (long long)(-1e9)
using namespace std;
ifstream cin("euro.in");
ofstream cout("euro.out");
int n,t,x;
long long dp[nmax],s[nmax];
int main()
{
    cin>>n>>t;
    for(int i=1;i<=n;i++){
        cin>>s[i];
        s[i]+=s[i-1];
        dp[i]=inf;
        for(int j=1;j<=i;j++)
            dp[i]=max(dp[i],dp[j-1]+(s[i]-s[j-1])*i-t);
    }
    cout<<dp[n];
    return 0;
}