Go: package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		w, h := io.NextInt(), io.NextInt()
		if w == 0 {
			break
		}
		xWall := make([][]int, h)
		yWall := make([][]int, h)
		for i := 0; i < h; i++ {
			xWall[i], yWall[i] = make([]int, w), make([]int, w)
			for j := 0; j < w; j++ {
				xWall[i][j], yWall[i][j] = -1, -1
			}
		}
		for i := 0; i < h*2-1; i++ {
			if i%2 == 0 {
				for j := 0; j < w-1; j++ {
					xWall[i/2][j] = io.NextInt()
				}
			} else {
				for j := 0; j < w; j++ {
					yWall[i/2][j] = io.NextInt()
				}
			}
		}
		//io.Println(bfs(w, h, xWall, yWall))
		fmt.Println(bfs(w, h, xWall, yWall))
	}
}

type P struct {
	x, y int
}

func bfs(w, h int, x, y [][]int) int {
	d := make([][]int, h)
	for i := 0; i < h; i++ {
		d[i] = make([]int, w)
	}
	q := list.New()
	q.PushBack(P{0, 0})
	d[0][0] = 1

	for q.Len() != 0 {
		pos := q.Remove(q.Front()).(P)
		if pos.x == w-1 && pos.y == h-1 {
			break
		}
		if pos.x > 0 && x[pos.y][pos.x-1] == 0 && d[pos.y][pos.x-1] == 0 {
			d[pos.y][pos.x-1] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x - 1, pos.y})
		}
		if pos.x < w-1 && x[pos.y][pos.x] == 0 && d[pos.y][pos.x+1] == 0 {
			d[pos.y][pos.x+1] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x + 1, pos.y})
		}
		if pos.y > 0 && y[pos.y-1][pos.x] == 0 && d[pos.y-1][pos.x] == 0 {
			d[pos.y-1][pos.x] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x, pos.y - 1})
		}
		if pos.y < h-1 && y[pos.y][pos.x] == 0 && d[pos.y+1][pos.x] == 0 {
			d[pos.y+1][pos.x] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x, pos.y + 1})
		}
	}
	return d[h-1][w-1]
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

Python: from collections import deque
while True:
    tmp = input().split(" ")
    w = int(tmp[0])
    h = int(tmp[1])
    if w == 0:
        break

    yoko_wall = []
    tate_wall = []

    for i in range(2*h-1):
        if i%2 == 0:
            omega = []
            for k in input().split(" ")[1:]:
                omega.append(int(k))
            yoko_wall.append(omega)
            #縦向きの壁の事
        else:
            omega2 = []
            for r in input().split(" "):
                omega2.append(int(r))
            tate_wall.append(omega2)

    #print("yoko_wall")
    #print(yoko_wall)
    #print("tate")
    #print(tate_wall)

    map_count = []
    for i in range(h):
        tmp = []
        for j in range(w):
            tmp.append(1000)
        map_count.append(tmp)

    q = deque([])
    q.append([0,0])
    map_count[0][0] = 0

    #tans
    while True:
        if len(q) == 0:
            print("0")
            break

        start = q.popleft()

        if start[0] == h-1 and start[1] == w-1:
            print(str(map_count[h-1][w-1]+1))
            break

        #4houkounoidou
        ue = [start[0]-1,start[1]]
        sita = [start[0]+1,start[1]]
        migi = [start[0],start[1]+1]
        hidari = [start[0],start[1]-1]

        #print("where to start" + str(start[0]) + ", " + str(start[1]))

        if ue[0] >= 0 and ue[0] < h and ue[1] >= 0 and ue[1] < w:
            #print("ue")
            #print(ue[0])
            #print(ue[1])
            if tate_wall[ue[0]][ue[1]] == 0:
                if map_count[ue[0]][ue[1]] == 1000:
                    map_count[ue[0]][ue[1]] = map_count[start[0]][start[1]] + 1
                    q.append(ue)
                    #print("new pattern ue")
                #else:
                    #print("already been there")

        if sita[0] >= 0 and sita[0] < h and sita[1] >= 0 and sita[1] < w:
            #print("sita")
            #print(sita[0])
            #print(sita[1])
            if tate_wall[start[0]][start[1]] == 0:
                #print("sita1")
                if map_count[sita[0]][sita[1]] == 1000:
                    #print("sita2")
                    map_count[sita[0]][sita[1]] = map_count[start[0]][start[1]] + 1
                    q.append(sita)
                    #print("new pattern sita")


        if migi[0] >= 0 and migi[0] < h and migi[1] >= 0 and migi[1] < w:
            #print("migi")
            #print(migi[0])
            #print(migi[1])
            if yoko_wall[start[0]][start[1]] == 0:
                if map_count[migi[0]][migi[1]] == 1000:
                    map_count[migi[0]][migi[1]] = map_count[start[0]][start[1]] + 1
                    q.append(migi)
                    #print("new pattern migi")
        #    else:
            #    print("couldnt go migi")

        if hidari[0] >= 0 and hidari[0] < h and hidari[1] >= 0 and hidari[1] < w:
            #print("hidari")
            #print(hidari[0])
            #print(hidari[1])
            if yoko_wall[hidari[0]][hidari[1]] == 0:
                if map_count[hidari[0]][hidari[1]] == 1000:
                    map_count[hidari[0]][hidari[1]] = map_count[start[0]][start[1]] + 1
                    q.append(hidari)