import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        ArrayList<ArrayList<Path>> graph = new ArrayList<>();
        int[] values = new int[n];
        for (int i = 0; i < n; i++) {
            graph.add(new ArrayList<>());
            values[i] = sc.nextInt();
            int m = sc.nextInt();
            for (int j = 0; j < m; j++) {
                int idx = sc.nextInt() - 1;
                if (values[idx] < values[i]) {
                    graph.get(idx).add(new Path(i, values[i] - values[idx]));
                }
            }
        }
        PriorityQueue<Path> queue = new PriorityQueue<>();
        long[] gains = new long[n];
        Arrays.fill(gains, -1);
        queue.add(new Path(0, 0));
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (gains[p.idx] >= p.value) {
                continue;
            }
            gains[p.idx] = p.value;
            for (Path x : graph.get(p.idx)) {
                queue.add(new Path(x.idx, x.value + p.value));
            }
            if (p.idx < n - 1) {
                queue.add(new Path(p.idx + 1, p.value));
            }
        }
        System.out.println(gains[n - 1]);
    }
    
    static class Path implements Comparable<Path> {
        int idx;
        long value;
        
        public Path(int idx, long value) {
            this.idx = idx;
            this.value = value;
        }
        
        public int compareTo(Path another) {
            if (idx == another.idx) {
                if (value == another.value) {
                    return 0;
                } else if (value < another.value) {
                    return 1;
                } else {
                    return -1;
                }
            } else {
                return idx - another.idx;
            }
        }
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}