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;
typedef long long ll;
#define f(i,x,n) for(int i=x;i<(int)(n);++i)
#define all(x) (x).begin(),(x).end()
const int mod=1000000007,MAX=1005,INF=1<<30;
vector<int> G[MAX];
int dis[MAX];

void BFS(){
    queue<int> Q;
    Q.push(0);
    while(!Q.empty()){
        int a=Q.front();Q.pop();
        
        for(int to:G[a]){
            if(dis[to]==INF){
                dis[to]=dis[a]+1;
                Q.push(to);
            }
        }
    }
}

int main(){
    
    std::ifstream in("text.txt");
    std::cin.rdbuf(in.rdbuf());
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    while(1){
        int H,W;cin>>W>>H;
        if(H+W==0) break;
        
        for(int i=0;i<H*W;i++){
            G[i].clear();
            dis[i]=INF;
        }
        dis[0]=0;
        
        for(int i=0;i<H;i++){
            for(int j=0;j<W-1;j++){
                int a;cin>>a;
                if(a==0){
                    G[i*W+j].push_back(i*W+j+1);
                    G[i*W+j+1].push_back(i*W+j);
                }
            }
            
            if(i==H-1) break;
            
            for(int j=0;j<W;j++){
                int a;cin>>a;
                if(a==0){
                    G[i*W+j].push_back((i+1)*W+j);
                    G[(i+1)*W+j].push_back(i*W+j);
                }
            }
        }
        
        BFS();
        
        if(dis[H*W-1]==INF) cout<<0<<endl;
        else cout<<dis[H*W-1]+1<<endl;
        
    }
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> P;
#define MAX_HW 35

int dx[4] = {1,0,-1,0};
int dy[4] = {0,-1,0,1};
int w,h;
int maze[MAX_HW*2-1][MAX_HW-1];
int sx=0,sy=0;
int gx,gy;

int d[MAX_HW][MAX_HW];

int bfs(){
    queue<P> que;
    memset(d,-1,sizeof(d));
    que.push(P(sx,sy));
    d[sx][sy]= 1;
    while(que.size()){
        P p=que.front();
        que.pop();
        if(p.first == gx && p.second == gy)break;
        for(int i=0;i<4;i++){
            int nx = p.first + dx[i], ny = p.second + dy[i];

            if(0 <= nx && nx <w && 0 <= ny&& ny < h && d[nx][ny] == -1){
                if(i==0){
                    if(maze[nx*2][ny+1]==0){
                        que.push(P(nx,ny));
                        d[nx][ny] = d[p.first][p.second] +1;
                    }
                }
                if(i==1){
                    if(maze[nx*2+1][ny]==0){
                        que.push(P(nx,ny));
                        d[nx][ny] = d[p.first][p.second] +1;
                    }
                }
                if(i==2){
                    if(maze[nx*2][ny]==0){
                        que.push(P(nx,ny));
                        d[nx][ny] = d[p.first][p.second] +1;
                    }
                }
                if(i==3){
                    if(maze[nx*2-1][ny]==0){
                        que.push(P(nx,ny));
                        d[nx][ny] = d[p.first][p.second] +1;
                    }
                }
            }
        }
    }
    if(que.size()){
        return d[gx][gy];
    }else{
        return 0;
    }
    

}


int main(){
    while(1){
        memset(maze,0,sizeof(maze));
        cin >> w >> h;
        gx = w-1;
        gy = h-1;
        if(w==0 && h==0)break;
        for(int i=0;i<2*h-1;i++){
            
            if(i%2==1){
                for(int j=0;j<w;j++){
                    cin >> maze[i][j];
                }
            }else{
                for(int j=1;j<w;j++){
                    cin >> maze[i][j];
                }
            }

        }
        cout << bfs() << endl;
    }


}