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)
}

C++: #include <iostream>
#include <queue>
#include <utility>
using namespace std;
typedef pair<int, int> P;

const int dx[4] = {0, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

int main()
{
    while(true){
        int w, h;
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        int rl[33][33], bf[33][33];
        for(int j = 0; j < w; j++) bf[0][j] = 1;
        for(int i = 0; i < h - 1; i++){
            rl[i][0] = rl[i][w] = 1;
            for(int j = 1; j < w; j++) cin >> rl[i][j];
            for(int j = 0; j < w; j++) cin >> bf[i + 1][j];
        }
        rl[h - 1][0] = rl[h - 1][w] = 1;
        for(int j = 1; j < w; j++) cin >> rl[h - 1][j];
        for(int j = 0; j < w; j++) bf[h][j] = 1;
        int d[33][33];
        for(int i = 0; i < 33; i++){
            for(int j = 0; j < 33; j++) d[i][j] = 10000;
        }
        d[1][1] = 1;
        queue<P> que;
        que.push(P(1, 1));
        while(que.size()){
            P now = que.front();
            que.pop();
            int i = now.first;
            int j = now.second;
            if(rl[i - 1][j] == 0){
                if(d[i][j + 1] > d[i][j] + 1){
                    d[i][j + 1] = d[i][j] + 1;
                    que.push(P(i, j + 1));
                }
            }
            if(bf[i][j - 1] == 0){
                if(d[i + 1][j] > d[i][j] + 1){
                    d[i + 1][j] = d[i][j] + 1;
                    que.push(P(i + 1, j));
                }
            }
            if(rl[i - 1][j - 1] == 0){
                if(d[i][j - 1] > d[i][j] + 1){
                    d[i][j - 1] = d[i][j] + 1;
                    que.push(P(i, j - 1));
                }
            }
            if(bf[i - 1][j - 1] == 0){
                if(d[i - 1][j] > d[i][j] + 1){
                    d[i - 1][j] = d[i][j] + 1;
                    que.push(P(i - 1, j));
                }
            }
        }
        if(d[h][w] == 10000) cout << 0 << endl;
        else cout << d[h][w] << endl;
    }
}