import java.util.*;
import java.io.*;
import java.io.BufferedReader;
import java.awt.Point;

public class buffet{
	public static final String TASKNAME = "buffet";
	public static long mod= 1000000007;
	public static Debug db;

	public static void main(String[] args) throws IOException {
//		InputReader in = new InputReader(System.in);
		PrintWriter out = new PrintWriter(System.out);
//		InputReader in = new InputReader(new FileInputStream(TASKNAME+".in"));
		InputReader in = new InputReader(new FileInputStream("3.in.txt"));
//		PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(TASKNAME+".out")));
		Autocompletion solver = new Autocompletion();
		db=new Debug(System.getSecurityManager()==null);
		solver.solve(1, in, out);
		out.close();
	}
	static class Autocompletion {

		public void solve(int testNumber, InputReader in, PrintWriter out) {
			int n=in.nextInt();
			int e=in.nextInt();
			ArrayList<Integer>[] adj=new ArrayList[n];
			int quality[]=new int[n];
			int sortedq[]=new int[n];
			for(int i=0;i<n;i++)adj[i]=new ArrayList<Integer>();
			for(int i=0;i<n;i++) {
				int q=in.nextInt();
				quality[i]=q;
				sortedq[i]=q;
				int d=in.nextInt();
				for(int j=0;j<d;j++) {
					adj[i].add(in.nextInt()-1);
				}
			}
			Arrays.sort(sortedq);
			int max[][]=new int[n][n];
			ArrayDeque<Triple> dq=new ArrayDeque<Triple>();
			for(int i=0;i<n;i++) {
				dq.add(new Triple(i,quality[i]));
				max[i][Arrays.binarySearch(sortedq, quality[i])]=quality[i];
			}
			while(!dq.isEmpty()) {
				Triple x=dq.remove();
				for(int y:adj[x.x]) {
					int temp=Arrays.binarySearch(sortedq, quality[y]);
					int temp2=Arrays.binarySearch(sortedq, x.y);
					if(quality[y]>x.y) {
						if(max[y][temp]<max[x.x][temp2]+quality[y]-e) {
							max[y][temp]=max[x.x][temp2]+quality[y]-e;
							dq.add(new Triple(y,quality[y]));
						}
					}
					if(max[y][temp2]<max[x.x][temp2]-e) {
						dq.add(new Triple(y,x.y));
						max[y][temp2]=max[x.x][temp2]-e;
					}
				}
			}
			int ret=0;
			for(int i=0;i<n;i++) {
				for(int j=0;j<n;j++) {
					ret=Math.max(ret, max[i][j]);
				}
			}
			out.println(ret);
		}
	}


static class Triple implements Comparable<Triple>{
	int x;//node
	int y;//index for qual
	Triple(int a, int b){
		x=a;
		y=b;
	}
	@Override
	public int compareTo(Triple arg0) {
		if(arg0.x!=x)return x-arg0.x;
		return y-arg0.y;
	}
}
	static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
        	return Long.parseLong(next());
        }
        public int[] nextIntArr(int n) {
        	int arr[]=new int[n];
        	for(int i=0;i<n;i++) {
        		arr[i]=this.nextInt();
        	}
        	return arr;
        }
    }
	public static class Debug {
        private boolean allowDebug;

        public Debug(boolean allowDebug) {
            this.allowDebug = allowDebug;
        }

        private void outputName(String name) {
            System.out.print(name + " = ");
        }

        public void debug(String name, int x) {
            if (!allowDebug) {
                return;
            }

            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, long x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, double x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, int[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, long[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, double[] x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.toString(x));
        }

        public void debug(String name, Object x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println("" + x);
        }

        public void debug(String name, Object... x) {
            if (!allowDebug) {
                return;
            }
            outputName(name);
            System.out.println(Arrays.deepToString(x));
        }
    }
}