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 <bits/stdc++.h>

using namespace std;

#define MAX 35
#define INF (1<<29)
typedef pair<int, int> pii;

int main()
{
    int W, H, x;
    while (cin >> W >> H, W) {
        bool wall[MAX][MAX][4];
        for (int i = 0; i < 2*H-1; i++) {
            for (int j = 0; j < W - !(i&1); j++) {
                cin >> x;
                if (!(i & 1)) {
                    wall[i/2][j][2] = wall[i/2][j+1][0] = x;
                } else {
                    wall[(i-1)/2][j][3] = wall[i/2+1][j][1] = x;
                }
            }
        }

        queue<pii> que;
        que.push(pii(0, 0));

        vector<vector<int>> d(H, vector<int>(W, INF));
        d[0][0] = 0;

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

        bool reachable = 0;
        
        while (!que.empty()) {
            pii p = que.front(); que.pop();
            int x = p.first, y = p.second;

            if (x == W-1 && y == H-1) {
                cout << d[y][x] + 1 << endl;
                reachable = 1;
                break;
            }
            
            for (int i = 0; i < 4; i++) {
                int nx = x + dx[i];
                int ny = y + dy[i];
                if (0 <= nx && nx < W && 0 <= ny && ny < H &&
                    !wall[y][x][i] &&
                    d[y][x] + 1 < d[ny][nx]) {
                    d[ny][nx] = d[y][x] + 1;
                    que.push(pii(nx, ny));
                }
            }
        }

        if (!reachable) {
            cout << 0 << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;


	

int main(){
	
	int a,b,i,j,x,y;
	int meiro[120][120];
	int map[120][120];
	queue<int> que;
	
	while(1){
	
		
		cin >> a >> b ;
		
		if(a==0&&b==0) return 0;
		
		
		for(i=0;i<100;i++){
			for(j=0;j<100;j++){
				map[i][j] = 0;
				meiro[i][j]=1;
			}
		}
		
		
		for(i=0;i<2*b-1;i++){
			
			if(i%2 == 0){
				for(j=0;j<a-1;j++){
					cin >> meiro[i][j];
				}
			}
			else {
				for(j=0;j<a;j++){
					cin >> meiro[i][j];
				}
			}
		}
		
		map[0][0] = 1;
		que.push(0);
		que.push(0);
		
		while(que.size()>0){
	
			
			x = que.front();
			que.pop();
			y = que.front();
			que.pop();
			
			//右へいけるか
			if(map[x][y+1]==0 && meiro[2*x][y]==0 && y<a-1) {
				map[x][y+1]=map[x][y]+1;
				que.push(x);
				que.push(y+1);
			}
			//下へいけるか
			if(map[x+1][y]==0 && meiro[2*x+1][y]==0 && x<b-1) {
				map[x+1][y]=map[x][y]+1;
				que.push(x+1);
				que.push(y);
			}
			//左へいけるか
			if(map[x][y-1]==0 && meiro[2*x][y-1]==0 && y>0) {
				map[x][y-1]=map[x][y]+1;
				que.push(x);
				que.push(y-1);
			}
			//上へいけるか
			if(map[x-1][y]==0 && meiro[2*x-1][y]==0 && x>0) {
				map[x-1][y]=map[x][y]+1;
				que.push(x-1);
				que.push(y);
			}
			
			
		}
		
		
		cout << map[b-1][a-1]<< endl;
	
	
	}
	
	
	
	
}