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 <queue>
#include <vector>
#include <iostream>

#define INF (1 << 29)

using namespace std;

const int dx[4] = { 0, 1, 0, -1 };
const int dy[4] = { -1, 0, 1, 0 };

int main()
{
	int H, W, T; vector<vector<vector<bool> > > M;

	while (true)
	{
		cin >> W >> H;

		if (W == 0 && H == 0) { break; }

		M = vector<vector<vector<bool> > >(H, vector<vector<bool> >(W, vector<bool>(4, false)));

		for (int i = 0; i < W; i++)
		{
			M[0][i][0] = true;
		}

		for (int i = 0; i < H; i++)
		{
			M[i][W - 1][1] = true;
		}

		for (int i = 0; i < W; i++)
		{
			M[H - 1][i][2] = true;
		}
		
		for (int i = 0; i < H; i++)
		{
			M[i][0][3] = true;
		}

		for (int i = 0; i < 2 * H - 1; i++)
		{
			for (int j = 0; j < (i % 2 == 0 ? W - 1 : W); j++)
			{
				cin >> T;

				if (T == 1)
				{
					if (i % 2 == 0)
					{
						M[i / 2][j][1] = true;
						M[i / 2][j + 1][3] = true;
					}
					else
					{
						M[i / 2][j][2] = true;
						M[i / 2 + 1][j][0] = true;
					}
				}
			}
		}

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

		queue<pair<int, int> > que; que.push(make_pair(0, 0));

		while (!que.empty())
		{
			pair<int, int> p1 = que.front(); que.pop();

			int x = p1.first;
			int y = p1.second;

			for (int dir = 0; dir < 4; dir++)
			{
				if (M[y][x][dir] == false)
				{
					if (dp[y + dy[dir]][x + dx[dir]] == INF)
					{
						dp[y + dy[dir]][x + dx[dir]] = dp[y][x] + 1;

						que.push(make_pair(x + dx[dir], y + dy[dir]));
					}
				}
			}
		}

		if (dp[H - 1][W - 1] == INF)
		{
			cout << 0 << endl;
		}
		else
		{
			cout << dp[H - 1][W - 1] << endl;
		}
	}

	return 0;
}

C++: #include<iostream>
#include<iomanip>
#include<math.h>
#include<algorithm>
#include<string>
#include<vector>
#include<queue>
#include<stack>
#include<set>
#include<map>
#define REP(i, N) for(ll i = 0; i < N; ++i)
#define FOR(i, a, b) for(ll i = a; i < b; ++i)
#define ALL(a) (a).begin(),(a).end()
#define pb push_back
#define INF (long long)1000000000
#define MOD 1000000007
#define EPS (long double) 1e-8
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> P;

int main() {
	while(1) {
		int w, h;
		cin>>w>>h;
		if(w == 0 && h== 0) break;
		int yoko[h][w - 1];
		int tate[h - 1][w];
		REP(i, 2 * h - 1) {
			if(i % 2 == 0) {
				REP(j, w - 1) cin>>yoko[i / 2][j];
			} else {
				REP(j, w) cin>>tate[i / 2][j];
			}
		}
		int d[h][w];
		REP(i, h) {
			REP(j, w) d[i][j] = INF;
		}
		d[0][0] = 0;
		queue<P> q;
		q.push(P(0, 0));
		while(!q.empty()) {
			P p = q.front();
			q.pop();
			if(p.first - 1 >= 0 && tate[p.first - 1][p.second] == 0 && d[p.first - 1][p.second] == INF) {
				d[p.first - 1][p.second] = d[p.first][p.second] + 1;
				q.push(P(p.first - 1, p.second));
			}
			if(p.first + 1 < h && tate[p.first][p.second] == 0 && d[p.first + 1][p.second] == INF) {
				d[p.first + 1][p.second] = d[p.first][p.second] + 1;
				q.push(P(p.first + 1, p.second));
			}
			if(p.second - 1 >= 0 && yoko[p.first][p.second - 1] == 0 && d[p.first][p.second - 1] == INF) {
				d[p.first][p.second - 1] = d[p.first][p.second] + 1;
				q.push(P(p.first, p.second - 1));
			}
			if(p.second + 1 < w && yoko[p.first][p.second] == 0 && d[p.first][p.second + 1] == INF) {
				d[p.first][p.second + 1] = d[p.first][p.second] + 1;
				q.push(P(p.first, p.second + 1));
			}
		}
		if(d[h - 1][w - 1] == INF) cout<<0<<endl;
		else cout<<d[h - 1][w - 1] + 1<<endl;
	}
}

C++: #include<iostream>
#include<queue>
#include<utility>
#include<cstring>
#define MP make_pair
using namespace std;
typedef pair<int, int> PII;

int w, h;
bool field[35][35];
int cost[35][35];
queue<PII> Q;

int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0};
bool judge(int x, int y)
{
  if(0 <= x && x < h && 0 <= y && y < w)
    return true;
  return false;
}

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

    if(!w && !h)
      break;

    memset(field, false, sizeof field);
    memset(cost, 0, sizeof cost);

    for(int i = 0; i < 2 * h - 1; i++)
      for(int j = 0; j < (i % 2 ? w : w - 1); j++)
	cin >> field[i][j];

    Q.push(MP(0, 0));
    cost[0][0] = 1;

    int nowcost = 0;
    while(!Q.empty()){
      int sz = Q.size();
      nowcost++;

      for(int i = 0; i < sz; i++){
	PII now = Q.front();
	Q.pop();

	for(int j = 0; j < 4; j++){
	  PII next = MP(now.first + dx[j], now.second + dy[j]);

	  if(judge(next.first, next.second) && !field[2 * now.first + dx[j]][dy[j] == -1 ? now.second - 1 : now.second] && cost[next.first][next.second] == 0){
	    cost[next.first][next.second] = nowcost + 1;
	    Q.push(next);
	  }
	}
      }
    }

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

  return 0;
}