#include <fstream>
using namespace std;

ifstream fin("euro.in");
ofstream fout("euro.out");

long long s1, s2, s, n, t, i;

int main(){
    fin >> n >> t;
    for(i = 1; i < n; i++){
        fin >> s2;
        s1 = s1 + s2;
        if(s1 < 0){
            s = s + i * s1 - t;
            s1 = 0;
        }
     }
    fin >> s2;
    s1 = s1 + s2;
    s = s + n * s1 - t;
    fout << s;
    return 0;
}