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 <cmath>
#include <iostream>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <tuple>
#include <algorithm>
#include <utility>
#include <iomanip>

#define int long long int
#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;

typedef pair<int, int> P;

const int INF = 1e15;
const int MOD = 1e9+7;

void solve(int w, int h){
    vector<vector<bool>> ud(h+1, vector<bool>(w, false));
    vector<vector<bool>> lr(h, vector<bool>(w+1, false));

    int x;
    rep(i, h-1){
        rep(j, w-1){
            cin >> x;
            if(x == 0){
                lr[i][j+1] = true;
            }
        }

        rep(j, w){
            cin >> x;
            if(x == 0){
                ud[i+1][j] = true;
            }
        }
    }
    rep(i, w-1){
        cin >> x;
        if(x == 0){
            lr[h-1][i+1] = true;
        }
    }

    queue<tuple<int, int, int>> que;
    que.emplace(0, 0, 1);
    vector<vector<int>> mark(h, vector<int>(w, 0));
    while(not que.empty()){
        tuple<int, int, int> p = que.front();
        que.pop();

        int x = get<0>(p);
        int y = get<1>(p);
        int d = get<2>(p);

        if(mark[x][y] != 0){
            continue;
        }

        mark[x][y] = d;

        if(ud[x][y]){
            que.emplace(x-1, y, d+1);
        }
        if(ud[x+1][y]){
            que.emplace(x+1, y, d+1);
        }
        if(lr[x][y]){
            que.emplace(x, y-1, d+1);
        }
        if(lr[x][y+1]){
            que.emplace(x, y+1, d+1);
        }
    }

    cout << mark[h-1][w-1] << endl;
}

signed main(){
    while(true){
        int w, h;
        cin >> w >> h;

        if(w == 0 && h == 0){
            break;
        }

        solve(w, h);
    }

    return 0;
}

C++: #include <iostream>
#include <string.h>
#include <queue>

#define W_MAX 32
#define H_MAX 32
#define mp make_pair


int maze[H_MAX][W_MAX];

int hline[H_MAX][W_MAX];
int wline[H_MAX][W_MAX];


using namespace std;

int main(void)
{
	int w,h;
	int i1,i2,i3;
	int x,y;
	int gool;
	int num;

	while(1){
		cin >> w >> h;
		if(w+h==0) break;

		memset(maze,-1,sizeof(maze));
		memset(hline,-1,sizeof(hline));
		memset(wline,-1,sizeof(wline));

		for(i1=1;i1<=h;i1++){
			for(i2=1;i2<=w;i2++){
				maze[i1][i2]=0;
			}
			
		}

		for(i1=1;i1<h;i1++){
			for(i2=1;i2<w;i2++) cin >> hline[i1][i2];
			for(i2=1;i2<=w;i2++) cin >> wline[i1][i2];
		}
		for(i2=1;i2<w;i2++) cin >> hline[i1][i2];

		queue<pair<int,int> > q;
		q.push(mp(1,1));
		maze[1][1]=1;
		gool=0;

		while(!q.empty()){
			x = q.front().first;
			y = q.front().second;
			q.pop();
			//cout << x << " " << y<< endl;
			if(x==w && y==h) {

				gool=1;
				break;
			}

			num=maze[y][x];

			/* 右　下　左　上*/
			if(maze[y][x+1]==0 && hline[y][x]==0) {
				maze[y][x+1]=num+1;
				q.push(mp(x+1,y));
			}
			if(maze[y+1][x]==0 && wline[y][x]==0) {
				maze[y+1][x]=num+1;
				q.push(mp(x,y+1));
			}
			if(maze[y][x-1]==0 && hline[y][x-1]==0) {
				maze[y][x-1]=num+1;
				q.push(mp(x-1,y));
			}
			if(maze[y-1][x]==0 && wline[y-1][x]==0) {
				maze[y-1][x]=num+1;
				q.push(mp(x,y-1));
			}	
		}

		/*for(i1=1;i1<=h;i1++){
			for(i2=1;i2<=w;i2++){
				cout << maze[i1][i2] << " ";
			}
			cout << endl;
		}*/

		if(gool==1) cout << maze[h][w] << endl;
		else cout << 0 << endl; 

	}

	return 0;
}