import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;

public class Main {

    private int w;

    private int h;

    /* [0]そこから上へ移動できるか。[1]そこから右へ移動できるか。[2]すでに踏破チェック済みか */
    private boolean[][] blocks;

    private static final String ODEKAKEDEKINAI = "Odekakedekinai..";

    private void initField(int w, int h) {
        this.w = w;
        this.h = h;
        blocks = new boolean[w * h][3];
    }

    private void execute() {
        if (w * h - 1 == 0) {
            System.out.println(0);
            System.exit(0);
        }
        /* block[0]を起点として、移動開始 */
        Set<Integer> next = new HashSet<Integer>();
        next.add(0);
        int stepCount = 0;
        while (true) {
            next = step(next);
            stepCount++;
            if (next.isEmpty()) {
                System.out.println(ODEKAKEDEKINAI);
                break;
            }
            if (next.contains(w * h - 1)) {
                System.out.println(stepCount);
                break;
            }
        }
    }

    private Set<Integer> step(Set<Integer> beforeBlocks) {
        Set<Integer> nextBlocks = new HashSet<Integer>();
        for (int number : beforeBlocks) {
            /* 現在numberに踏破済みのフラグ(blocks[number][2]=true)を立てる */
            blocks[number][2] = true;
            /* 上移動チェック */
            if (blocks[number][0] && !blocks[number + w][2]) {
                nextBlocks.add(number + w);
            }
            /* 下移動チェック */
            if (number > w && blocks[number - w][0] && !blocks[number - w][2]) {
                nextBlocks.add(number - w);
            }
            /* 左移動チェック */
            if (number % w != 0 && blocks[number - 1][1] && !blocks[number - 1][2]) {
                nextBlocks.add(number - 1);
            }
            /* 右移動チェック */
            if (blocks[number][1] && !blocks[number + 1][2]) {
                nextBlocks.add(number + 1);
            }
        }
        return nextBlocks;
    }

    private void footprint(int min, int max) {
        if (min / w == max / w) {
            /* 横の移動 = minとmaxをwで割ったときの値が等しい */
            for (int i = min; i < max; i++) {
                /* 左側(数が小さいほうのblock)から右へと移動できるので、blocks[i][1]をtrue */
                blocks[i][1] = true;
            }
        } else {
            /* 縦の移動 */
            for (int i = min; i < max; i += w) {
                /* 下側(数が小さいほうのblock)から上へと移動できるので、blocks[i][0]をtrue */
                blocks[i][0] = true;
            }
        }
    }

    public static void main(String[] args) {
        FastScanner cin = new FastScanner();
        Main snow = new Main();
        int w = Integer.parseInt(cin.next());
        int h = Integer.parseInt(cin.next());
        snow.initField(w, h);
        Map<Integer, Set<Integer>> checkedMap = new HashMap<Integer, Set<Integer>>();
        int limit = Integer.parseInt(cin.next());
        for (int i = 0; i < limit; i++) {
            int index = Integer.parseInt(cin.next());
            int[] currentArray = new int[2];
            currentArray[1] = Integer.parseInt(cin.next());
            for (int j = 0; j < index; j++) {
                currentArray[j % 2] = Integer.parseInt(cin.next());
                int min = Math.min(currentArray[0], currentArray[1]);
                int max = Math.max(currentArray[0], currentArray[1]);
                if (!checkedMap.containsKey(min)) {
                    Set<Integer> set = new HashSet<Integer>();
                    set.add(max);
                    checkedMap.put(min, set);
                } else {
                    Set<Integer> set = checkedMap.get(min);
                    if (set.contains(max)) {
                        continue;
                    }
                    set.add(max);
                }
                snow.footprint(min, max);
            }
        }
        snow.execute();
    }

}

/**
 * http://qiita.com/p_shiki37/items/a0f6aac33bf60f5f65e4 よりFastScannerをお借りして実装。
 */
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() {
        if (hasNextByte())
            return buffer[ptr++];
        else
            return -1;
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    }

    public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr]))
            ptr++;
        return hasNextByte();
    }

    public String next() {
        if (!hasNext())
            throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext())
            throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
            throw new NumberFormatException();
        return (int) nl;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }
}