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 <map>
#include <queue>

using namespace std;

typedef pair<int, int> P;
typedef pair<int, P> CP;

int main() {
    int w, h, count;
    int dx[] = {-1, 0, 1, 0};
    int dy[] = {0, -1, 0, 1};
    int wall[60][60];
    bool has_arrived[30][30];
    while (true) {
        queue<CP> q;
        cin >> w >> h;
        if (w == 0 && h == 0) {
            break;
        }
        for (int y=0; y<2*h-1; y++) {
            for (int x=0; x<w-1+y%2; x++) {
                cin >> wall[x][y];
            }
        }
        for (int y=0; y<h; y++) {
            for (int x=0; x<w; x++) {
                has_arrived[x][y] = false;
            }
        }
        q.push(CP(1, P(0, 0)));
        has_arrived[0][0] = true;
        while (q.size() > 0) {
            count = q.front().first;
            P pos = q.front().second;
            int x = pos.first;
            int y = pos.second;
            q.pop();
            if (x == w-1 && y == h-1) {
                break;
            }
            for (int i=0; i<4; i++) {
                int nx = x+dx[i];
                int ny = y+dy[i];
                if (nx < 0 || w <= nx || ny < 0 || h <= ny) {
                    continue;
                }
                if (has_arrived[nx][ny]) {
                    continue;
                }
                if (wall[min(x, nx)][ny+y] != 0) {
                    continue;
                }
                q.push(CP(count+1, P(nx, ny)));
                has_arrived[nx][ny] = true;
            }
        }
        if (has_arrived[w-1][h-1]) {
            cout << count << endl;
        }
        else {
            cout << 0 << endl;
        }
    }
    return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;
int w,h,count;
typedef struct{
	int x;
	int y;
}POS;
POS start,goal,flag;

int map[31][31];
int wall[100][100];
queue <POS> q;

int check(){
	POS nextpos;
	q.push(start);
	q.push(flag);
	while(count<=w*h){
		POS pos=q.front();
		q.pop();
		if(pos.x==goal.x&&pos.y==goal.y)return count;
		if(pos.x==-1){
			count++;
			q.push(flag);
		}else{
			if(pos.x>0&&wall[pos.x*2-1][pos.y]==0 &&map[pos.x-1][pos.y]==0){
				nextpos.x=pos.x-1;
				nextpos.y=pos.y;
				q.push(nextpos);
				map[nextpos.x][nextpos.y]=1;
			}

			if(pos.y>0&&wall[pos.x*2][pos.y-1]==0 &&map[pos.x][pos.y-1]==0){
				nextpos.x=pos.x;
				nextpos.y=pos.y-1;
				q.push(nextpos);
				map[nextpos.x][nextpos.y]=1;
			}

			if(pos.x<h-1&&wall[pos.x*2+1][pos.y]==0 &&map[pos.x+1][pos.y]==0){
				nextpos.x=pos.x+1;
				nextpos.y=pos.y;
				q.push(nextpos);
				map[nextpos.x][nextpos.y]=1;
			}

			if(pos.y<w-1&&wall[pos.x*2][pos.y]==0 &&map[pos.x][pos.y+1]==0){
				nextpos.x=pos.x;
				nextpos.y=pos.y+1;
				q.push(nextpos);
				map[nextpos.x][nextpos.y]=1;
			}

		}
		//cout <<pos.x <<" " <<pos.y <<endl;
	}
	return 0;
}

int main(){
	start.x=start.y=0;
	flag.x=flag.y=-1;
	while(1){
		cin >>w >>h;
		if(!(w||h))break;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				map[i][j]=0;
			}
		}
		for(int i=0;i<2*h-1;i++){
			for(int j=0;j<w;j++){
				if(j==w-1&&i%2==0)continue;
				cin >>wall[i][j];
			}
		}
		count=1;
		goal.x=h-1;
		goal.y=w-1;
		cout << check()<<endl;
		while(!q.empty())q.pop();
	}
}