#include <cstdio>

#define file_in "euro.in"
#define file_out "euro.out"

#define Nmax 34600

int n,t;
int sum,i,v[Nmax];
long long rez;

int main()
{
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d", &n,&t);
	for (i=1;i<=n;++i)
		 scanf("%d", &v[i]);
	
	//i=1;
	sum=0;
	rez=0;
	for (i=1;i<=n;++i)
	{
		if (sum>=0)
		{
			sum+=v[i];
		}
		else
		{
			rez=rez+sum*(i-1)-t;
			//printf("%d\n", sum);
			sum=v[i];
		}
	}

	printf("%lld", rez+sum*n-t);
	
	fclose(stdin);
	fclose(stdout);
	
	return 0;
}