#include <iostream>
#include <fstream>

#define f1 "euro.in"
#define f2 "euro.out"
using namespace std;

int main(){
    ifstream fi;fi.open(f1);
    ofstream fo;fo.open(f2);
    long a[35000];
    long n,t;
    fi>>n>>t;
    //fo<<n<<" "<<t<<endl;
    for (int i=0;i<n;i++){
        fi>>a[i];
        //fo<<a[i]<<endl;
    }
    long tong,kq;
    int z;
    kq=0;tong=0;
    z=0;
    for (int i=0;i<n;i++){
        tong+=a[i];
        if (tong<0) {
            if (i==n-1) z=1;
            kq+=tong*(i+1)-t;
            tong=0;
            //fo<<kq<<endl;
        }
    }
    if (z=0) kq+=tong*n-t;
    fo<<kq;
    fi.close();
    fo.close();
    return 0;
}