#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from collections import deque

W, H, Q = map(int, readline().split())
query = readlines()

if H == W == 1:
    print(0)
    exit()

N = H * W
horizonal_max = list(range(N))
vertical_max = list(range(N))

for line in query[1::2]:
    B = map(int, line.split())
    x = next(B)
    for y in B:
        a, b = x, y
        if a > b:
            a, b = b, a
        if b - a < W:
            if horizonal_max[a] < b:
                horizonal_max[a] = b
        else:
            if vertical_max[a] < b:
                vertical_max[a] = b
        x = y

for i in range(N):
    h = horizonal_max[i]
    if h > i:
        if horizonal_max[i + 1] < h:
            horizonal_max[i + 1] = h
    v = vertical_max[i]
    if v > i:
        if vertical_max[i + W] < v:
            vertical_max[i + W] = v

INF = N + 10
dist = [INF] * N
dist[0] = 0
q = deque([0])
goal = N - 1


def gen_w(v):
    if horizonal_max[v] > v:
        yield v + 1
    if v and horizonal_max[v - 1] >= v:
        yield v - 1
    if vertical_max[v] > v:
        yield v + W
    if v >= W and vertical_max[v - W] >= v:
        yield v - W


while q:
    v = q.popleft()
    dw = dist[v] + 1

    for w in gen_w(v):
        if dist[w] <= dw:
            continue
        if w == goal:
            print(dw)
            exit()
        dist[w] = dw
        q.append(w)

print('Odekakedekinai..')