// まずTLEとなるでしょう・・・

import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Map;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;

public class Main {

    public static void main(String... args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int w = sc.nextInt();
        int h = sc.nextInt();
        int n = sc.nextInt();

        Map<Integer, Set<Integer>> map = new HashMap<>();
        while (sc.hasNextInt()) {
            int m = sc.nextInt();
            int b = sc.nextInt();
            for (int i = 0; i < m; i++) {
                int bTo = sc.nextInt();

                int offset;
                if (bTo >= b + w) {
                    offset = w;
                } else if (bTo > b) {
                    offset = 1;
                } else if (bTo <= b - w) {
                    offset = -w;
                } else {
                    offset = -1;
                }

                while (b != bTo) {
                    map.computeIfAbsent(b, x -> new HashSet());
                    map.get(b).add(b + offset);
                    map.computeIfAbsent(b + offset, x -> new HashSet());
                    map.get(b + offset).add(b);
                    b += offset;
                }
            }
        }

        Queue<Point> queue = new LinkedList<>();
        queue.add(new Point(0, 0));
        Set<Integer> visited = new HashSet<>();
        visited.add(0);

        Point point;
        while ((point = queue.poll()) != null) {
            Set<Integer> indexesTo = map.get(point.index);
            if (indexesTo != null) {
                for (Integer indexTo : indexesTo) {
                    if (indexTo == w * h - 1) {
                        System.out.println(point.move + 1);
                        System.exit(0);
                    }
                    if (!visited.contains(indexTo)) {
                        visited.add(indexTo);
                        queue.add(new Point(indexTo, point.move + 1));
                    }
                }
            }
        }

        System.out.println("Odekakedekinai..");
    }
}

class Point {

    final int index;
    final int move;

    Point(int index, int move) {
        this.index = index;
        this.move = move;
    }

    @Override
    public String toString() {
        return String.format("index: %d, move: %d", index, move);
    }
}