#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 510;

ll ps[N],vis[N],n,m,zuo,you,res,zuo_n,you_n;

int main(){
	freopen("Eulalover.in","r",stdin);
	freopen("Eulalover.out","w",stdout);
	int fg=1;
	int p0s; 
	scanf("%lld%lld",&n,&m);
	for(int i=1;i<=n;i++){
		scanf("%lld",&ps[i]);
		if(ps[i]==0){
			fg=0;
			p0s=i;
			res+=m; 
		}
	}
	if(fg){
		ps[++n]=0;
	}
	sort(ps+1,ps+1+n);
	for(int i=1;i<=n;i++){
//		cout<<ps[i]<<"www";
//		cout<<"RR"<<zuo<<" "<<you<<endl;
		if(ps[i]<0){
			zuo+=(m-(0-ps[i]));
			zuo_n++;
		}
		if(ps[i]==0&&fg){
			p0s=i;
			vis[i]++;
//			cout<<vis[i]<<"FFF"<<endl;
		}
		if(ps[i]>0){
			you_n++;
			you+=(m-ps[i]);
		}
	}
	int t=0;
//	for(int i=1;i<=n;i++)cout<<vis[i]<<" ";
//	cout<<endl;
//	cout<<zuo<<" "<<zuo_n<<" "<<you<<" "<<you_n<<endl; 
	for(int i=1;i<n;i++){
		if(t>=m)break;
		else if(zuo_n==0&&you_n==0)break;
		if(zuo>=you){
//			cout<<"左"<<endl; 
			int rr=p0s-1;
//			cout<<vis[rr]<<"rr"<<endl;
			while(vis[rr]&&rr>0)rr--;
			t+=(ps[p0s]-ps[rr]);
			you-=(ps[p0s]-ps[rr])*2*you_n;
			p0s=rr;
			vis[p0s]++;
			res+=m-t;
			zuo-=m-t;
			zuo_n--;
		}else if(zuo<you){
//			cout<<"右"<<endl; 
			int rr=p0s+1;
//			cout<<vis[rr]<<"rr"<<endl;
			while(vis[rr]&&rr<n)rr++;
			t+=(ps[rr]-ps[p0s]);
			zuo-=(ps[rr]-ps[p0s])*2*zuo_n;
			p0s=rr;
			vis[p0s]++;
			res+=m-t;
			you-=m-t;
			you_n--;
		}
//		cout<<ps[p0s]<<" "<<t<<" "<<res<<endl;
//		cout<<"now"<<zuo<<" "<<zuo_n<<" "<<you<<" "<<you_n<<endl;
	}
	printf("%lld",res);
	return 0;
}