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 INF -1
typedef pair<int,int> P;
#define MAX_H 59
#define MAX_W 59
char maze[MAX_H][MAX_W+1];
int h,w;
int sx,sy;
int gx,gy;
int dp[MAX_H][MAX_W];
const int dx[4]={1,0,-1,0};
const int dy[4]={0,-1,0,1};
int main(){
    while(scanf("%d%d%*c",&w,&h)){
        int i,j;
        sx=0;
        sy=0;
        gx=2*h-2;
        gy=2*w-2;
        queue<P>que;
        P p;
        if(w==0 && h==0){
            break;
        }
        for(i=0;i<2*h-1;i++){
            for(j=0;j<2*w-2;j++){
                maze[i][j]=getchar();
            }
            if(i%2==0){
                maze[i][j]=' ';
            }else{
                maze[i][j]=getchar();
            }
            getchar();
        }
        for(i=0;i<2*h-1;i++){
            for(j=0;j<2*w-1;j++){
                dp[i][j]=INF;
            }
        }
        que.push(P(sx,sy));
        dp[sx][sy]=1;
        while(que.size()){
            p=que.front();
            que.pop();
            if(p.first==gx && p.second==gy){
                break;
            }
            for(i=0;i<4;i++){
                int nx=p.first+2*dx[i];
                int ny=p.second+2*dy[i];
                if(0<=nx && nx<(2*h-1) && 0<=ny && ny <(2*w-1) && maze[p.first+dx[i]][p.second+dy[i]]== '0' && dp[nx][ny]==INF){
                    que.push(P(nx,ny));
                    dp[nx][ny]=dp[p.first][p.second]+1;
                }
            }
        }
        /*for(j=0;j<2*h-1;j++){
            for(i=0;i<2*w-1;i++){
                printf("%2d",dp[i][j]);
            }
            printf("\n");
        }*/
        while(que.size()){
            que.pop();
        }
        if(dp[gx][gy]==INF){
            cout<<0<<endl;
        }else{
            cout<<dp[gx][gy]<<endl;
        }   
    }  
    return 0;
}

C++: #include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

#define repi(i,a,b) for(int i=(a);i<(b);i++)
#define rep(i,a) repi(i,0,a)
#define repd(i,a,b) for(int i=(a);i>=(b);i--)
#define repit(i,a) for(__typeof((a).begin()) i=(a).begin();i!=(a).end();i++)

#define all(u) (u).begin(),(u).end()
#define rall(u) (u).rbegin(),(u).rend()
#define UNIQUE(u) (u).erase(unique(all(u)),(u).end())

#define pb push_back
#define mp make_pair
#define INF 1e9
#define EPS 1e-9
#define PI acos(-1.0)

using namespace std;

typedef long long ll;
typedef vector<int> vi;

const int MAX = 32;
int h, w;
bool inrange(int x, int y){
    return x >= 0 && y >= 0 && x < w && y < h;
}
int wall[4][MAX][MAX], done[MAX][MAX];
const int dx[] = {0, 1, 0,-1};
const int dy[] = {-1, 0, 1, 0};
struct node {
    int x, y, step;
};
int main()
{
    while(cin >> w >> h, w||h) {
        memset(wall, 0, sizeof(wall));
        // input
        rep(j, w) wall[0][0][j] = wall[2][h-1][j] = 1;
        rep(i, h) {
            wall[1][i][w-1] = wall[3][i][0] = 1;
            rep(j, w-1) {
                cin >> wall[1][i][j];
                wall[3][i][j+1] = wall[1][i][j];
            }
            if(i == h-1) break;
            rep(j, w) {
                cin >> wall[2][i][j];
                wall[0][i+1][j] = wall[2][i][j];
            }
        }

        queue<node> q;
        memset(done, 0, sizeof(done));
        q.push((node){0, 0, 0});
        int ans = 0;
        while(q.size()) {
            int x = q.front().x;
            int y = q.front().y;
            int step = q.front().step;
            q.pop();
            if(done[x][y]) continue;
            done[x][y] = 1;
            if(x == w-1 && y == h-1) {
                ans = step+1;
                break;
            }
            rep(i, 4) if(!wall[i][y][x]) {
                int nx = x + dx[i];
                int ny = y + dy[i];
                if(inrange(nx, ny)) q.push((node){nx, ny, step+1});
            }
        }
        cout << ans << endl;

    }
    return 0;
}