from sys import stdin
from Queue import deque
dxy = ((1,0),(0,1),(-1,0),(0,-1))
W,H,N = map(int,stdin.readline().split())
MD = W*H+1
EX = [[0]*(W+2) for j in xrange(H)]
EY = [[0]*(H+2) for i in xrange(W)]
for i in xrange(N):
    M = int(stdin.readline())
    B = map(int,stdin.readline().split())
    for j in xrange(M):
        x = B[j]%W; y = B[j]/W; nx = B[j+1]%W; ny = B[j+1]/W
        if y == ny:
            if x < nx: EX[y][x+1]+=1; EX[y][nx+1]-=1
            else: EX[y][nx+1]+=1; EX[y][x+1]-=1
        else:
            if y < ny: EY[x][y+1]+=1; EY[x][ny+1]-=1
            else: EY[x][ny+1]+=1; EY[x][y+1]-=1
        x,y = nx,ny
for j in xrange(H):
    for i in xrange(1,W):EX[j][i+1] += EX[j][i]
for i in xrange(W):
    for j in xrange(1,H):EY[i][j+1] += EY[i][j]
D = [[MD]*W for i in xrange(H)]
D[0][0] = 0; G = W+H-2
Q = deque([(0,0,0)])
while Q:
    x,y,d = Q.popleft()
    if x+y == G:
        print d; break
    for dx,dy in dxy:
        if dx > 0:
            nx = x + 1
            if EX[y][nx]>0 and D[y][nx] > d+1:
                D[y][nx] = d+1; Q.append((nx,y,d+1))
        elif dx < 0:
            nx = x - 1
            if EX[y][x]>0 and D[y][nx] > d+1:
                D[y][nx] = d+1; Q.append((nx,y,d+1))
        elif dy > 0:
            ny = y + 1
            if EY[x][ny]>0 and D[ny][x] > d+1:
                D[ny][x] = d+1; Q.append((x,ny,d+1))
        else:
            ny = y - 1
            if EY[x][y]>0 and D[ny][x] > d+1:
                D[ny][x] = d+1; Q.append((x,ny,d+1))
else:
    print "Odekakedekinai.."