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 <algorithm>
#include <queue>
#include <utility>
using namespace std;

const int INF = (int)1e8;
typedef pair<int, int> P;

int main() {
  while(true) {
    int W, H; cin >> W >> H;
    if(W == 0 && H == 0) break;
    bool wall[H][W][4];
    const int dx[4] = { 1, 0, -1, 0 };
    const int dy[4] = { 0, -1, 0, 1 };
    for(int i = 0; i < H; i++) {
      for(int j = 0; j < W; j++) {
        wall[i][j][0] = false;
        wall[i][j][1] = false;
        wall[i][j][2] = false;
        wall[i][j][3] = false;
        if(i == 0) wall[i][j][1] = true;
        if(i == H - 1) wall[i][j][3] = true;
        if(j == 0) wall[i][j][2] = true;
        if(j == W - 1) wall[i][j][0] = true;
      }
    }
    for(int i = 0 ; i < H; i++) {
      for(int j = 0; j < W - 1; j++) {
        int s; cin >> s;
        if(s) {
          wall[i][j][0] = true;
          wall[i][j+1][2] = true;
        }
      }
      if(i != H - 1) {
        for(int j = 0; j < W; j++) {
          int s; cin >> s;
          if(s) {
            wall[i][j][3] = true;
            wall[i+1][j][1] = true;
          }
        }
      }
    }

    int d[H][W];
    for(int i = 0; i < H; i++)
      for(int j = 0; j < W; j++) d[i][j] = INF;
    queue<P> Q;
    Q.push(P(0, 0));
    d[0][0] = 1;
    while(!Q.empty()) {
      P p = Q.front(); Q.pop();
      for(int i = 0; i < 4; i++) {
        int ny = p.first + dy[i];
        int nx = p.second + dx[i];
        if(0 <= ny && ny < H && 0 <= nx && nx < W && d[ny][nx] == INF && wall[p.first][p.second][i] == 0) {
          d[ny][nx] = d[p.first][p.second] + 1;
          Q.push(P(ny, nx));
        }
      }
    }
    if(d[H-1][W-1] != INF) {
      cout << d[H-1][W-1] << endl;
    }
    else {
      cout << 0 << endl;
    }
  }
}

C++: #include<cstdio>
#include<queue>
#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<set>

using namespace std;

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

class P{
	public:
	int x,y,val;
	P(int x,int y,int val):x(x),y(y),val(val){}
};

int main(){
	
	A:;
	int w,h;
	cin>>w>>h;
	if(w==0 && h==0)return 0;
	
	vector<int> tall[33];
	vector<int> wall[33];
	
	rep(i,h){
		rep(j,w-1){
			int a;
			cin>>a;
			tall[i].push_back(a);
		}
		
		if(i==h-1)continue;
		rep(j,w){
			int a;
			cin>>a;
			wall[i].push_back(a);
		}
	}
	
	queue<P> que;
	que.push(P(0,0,0));
	
	int visit[33][33]={0};
	int ans = 0;
	while(1){
		if(que.empty())break;
		
		P u = que.front();
		que.pop();
		
		int x = u.x;
		int y = u.y;
		int val = u.val;
		
		if(visit[x][y]==1)continue;
		visit[x][y]=1;
		
		if(x==w-1 && y==h-1){
			ans = val;
			break;
		}
		
		if(x<w-1 && tall[y][x]==0)que.push(P(x+1,y,val+1));
		if(x-1>=0 && tall[y][x-1]==0)que.push(P(x-1,y,val+1));
		if(y<h-1 && wall[y][x]==0)que.push(P(x,y+1,val+1));
		if(y-1>=0 && wall[y-1][x]==0)que.push(P(x,y-1,val+1));
	}
	
	if(ans==0)puts("0");
	else printf("%d\n",ans+1);
	
	goto A;
}

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

typedef struct{
	int f; //first
	int s; //second
}point;

int main(){
	while(1){	
		int w, h;
		int f[60][60];
		int field[30][30];
		int df[4]={0, -1, 0, 1}, ds[4]={1, 0, -1, 0};
		
		scanf(" %d %d", &w, &h);
		if(w==0) break;
		
		for(int i=0; i<2*h-1; ++i){
			int t;
			if(i%2==1) t=w;
			else t=w-1;
			for(int j=0; j<t; ++j) scanf("  %d", &f[i][j]);
		}
	
		for(int i=0; i<30; ++i)
		for(int j=0; j<30; ++j)
		field[i][j]=0;
		
		point start, goal;
		start.f=0;
		start.s=0;
		goal.f=h-1;
		goal.s=w-1;
		
		queue<point> que;
		field[start.f][start.s]=1;
		que.push(start);
		while(!que.empty()){
			point now=que.front();
			que.pop();
			
			int nf, ns;
			if(now.s+1<w &&f[2*now.f][now.s]==0 && field[now.f][now.s+1]==0){ //右側
				nf=now.f;
				ns=now.s+1;
				field[nf][ns]=field[now.f][now.s]+1;
				point tmp;
				tmp.f=nf;
				tmp.s=ns;
				que.push(tmp);
			}
			if(now.s-1>=0 &&f[2*now.f][now.s-1]==0 && field[now.f][now.s-1]==0){ //左側
				nf=now.f;
				ns=now.s-1;
				field[nf][ns]=field[now.f][now.s]+1;
				point tmp;
				tmp.f=nf;
				tmp.s=ns;
				que.push(tmp);
			}
			if(now.f-1>=0 &&f[2*now.f-1][now.s]==0 && field[now.f-1][now.s]==0){ //上側
				nf=now.f-1;
				ns=now.s;
				field[nf][ns]=field[now.f][now.s]+1;
				point tmp;
				tmp.f=nf;
				tmp.s=ns;
				que.push(tmp);
			}
			if(now.f+1<h &&f[2*now.f+1][now.s]==0 && field[now.f+1][now.s]==0){ //下側
				nf=now.f+1;
				ns=now.s;
				field[nf][ns]=field[now.f][now.s]+1;
				point tmp;
				tmp.f=nf;
				tmp.s=ns;
				que.push(tmp);
			}
		}
	
		printf("%d\n", field[goal.f][goal.s]);
	}
	return 0;
}