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<limits.h>
#include<queue>
using namespace std;
static int dy[] = { 0, 1, 0, -1 };
static int dx[] = { 1, 0, -1, 0 };
static int map[60][60];
static int path[60][60];
typedef struct d Data;
struct d
{
	int x;
	int y;
	int count;
};

int main()
{
	int w, h;
	while (cin >> w >> h && w != 0 || h != 0)
	{
		for (int i = 0; i < h + (h - 1); i++)
		{
			for (int j = 0; j < w + (w - 1); j++)
			{
				map[i][j] = 0;
			}
		}

		for (int i = 0; i < h + (h - 1); i++)
		{
			for (int j = (i + 1) % 2; j < w + (w - 1); j += 2)
			{
				cin >> map[i][j];
			}
		}

		for (int i = 0; i < h + (h - 1); i++)
		{
			for (int j = 0; j < w + (w - 1); j++)
			{
				cout << map[i][j] << " ";
			}
			cout << endl;
		}

		for (int i = 0; i < h + (h - 1); i++)
		{
			for (int j = 0; j < w + (w - 1); j++)
			{
				path[i][j] = 0;
			}
		}

		int ans = 0;
		queue<Data> q;
		Data data;
		data.x = 0;
		data.y = 0;
		data.count = 1;
		q.push(data);
		path[0][0] = 1;
		while (q.size() > 0)
		{
			Data dd = q.front(); 
			q.pop();
			if (dd.x == w + (w - 1) - 1 && dd.y == h + (h - 1) - 1)
			{
				ans = dd.count;
				break;
			}
			for (int i = 0; i < 4; i++)
			{
				int nx = dd.x + dx[i] * 2;
				int ny = dd.y + dy[i] * 2;

				if (nx < 0 || ny < 0 || nx >= w + (w - 1) || ny >= h + (h - 1))continue;
				if (map[dd.y + dy[i]][dd.x + dx[i]] == 1)continue;
				if (path[ny][nx] == 1)continue;
				Data ddd;
				ddd.x = nx;
				ddd.y = ny;
				ddd.count = dd.count + 1;
				q.push(ddd);
				path[ddd.y][ddd.x] = 1;
			}
		}
		cout << ans << endl;


	}
	return 0;
}

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

#define M_PI       3.14159265358979323846   // pi

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> VI;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> t3;
typedef tuple<ll, ll, ll, ll> t4;
typedef tuple<ll, ll, ll, ll, ll> t5;

#define rep(a,n) for(ll a = 0;a < n;a++)
#define repi(a,b,n) for(ll a = b;a < n;a++)

using namespace std;

static const ll INF = 1e15;

int main() {
	while (true) {
		ll w, h;
		cin >> w >> h;
		if (w == 0 && h == 0) return 0;
		map<P, set<P>> graph;
		rep(i, h - 1) {
			rep(j, w - 1) {
				int b;
				cin >> b;
				if (!b) {
					graph[{j, i}].insert({ j + 1,i });
					graph[{j + 1, i}].insert({ j ,i });
				}	
			}
			rep(j, w) {
				int b;
				cin >> b;
				if (!b) {
					graph[{j, i}].insert({ j ,i + 1 });
					graph[{j, i + 1}].insert({ j ,i });
				}
			}
		}
		rep(j, w - 1) {
			int b;
			cin >> b;
			if (!b) {
				graph[{j, h - 1}].insert({ j + 1,h - 1 });
				graph[{j + 1, h - 1}].insert({ j ,h - 1 });
			}
		}
		vector<vector<ll>> dist(h, vector<ll>(w, INF));
		queue<t3> q;
		q.emplace(0, 0, 1);
		while (!q.empty()) {
			auto t = q.front(); q.pop();
			ll x, y, d;
			tie(x, y, d) = t;
			if (dist[y][x] <= d) {
				continue;
			}
			dist[y][x] = d;
			for (auto p : graph[{x, y}]) {
				if (dist[p.second][p.first] <= d + 1) {
					continue;
				}
				q.emplace(p.first, p.second, d + 1);
			}
		}
		if (dist[h - 1][w - 1] == INF) {
			cout << 0 << endl;

		}
		else {
			cout << dist[h - 1][w - 1] << endl;

		}
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
#include <functional>

using namespace std;

struct St{
  int x, y, cst;

  St() {}
  St(int _x, int _y, int _cst): x(_x), y(_y), cst(_cst) {}

  bool operator>(const St& st) const{
    return cst > st.cst;
  }

  bool operator<(const St& st) const{
    return cst < st.cst;
  }
};

int h, w;
bool a[31][31][31][31];
int xdir[4] = {0, 1, 0, -1}, ydir[4] = {-1, 0, 1, 0};

int bfs()
{
  bool vis[31][31];
  priority_queue<St, vector<St>, greater<St> > que;
  que.push(St(0, 0, 1));
  fill(&vis[0][0], &vis[31][0], true);
  vis[0][0] = false;

  while(!que.empty()){
    St st = que.top();
    que.pop();

    if(st.x == w-1 && st.y == h-1) return st.cst;

    for(int i = 0; i < 4; ++i){
      int dx = st.x+xdir[i], dy = st.y+ydir[i];
      if(0 <= dx && dx < w && 0 <= dy && dy < h && vis[dy][dx] && a[dy][dx][st.y][st.x]){
	vis[dy][dx] = false;
	que.push(St(dx, dy, st.cst+1));
      }
    }
  }

  return 0;
}

int main()
{
  int s, t;

  while(cin>>w>>h && w+h){
    fill(&a[0][0][0][0], &a[31][0][0][0], false);
    t = 0;
    for(int i = 0; i < 2*h-1; ++i){
      if(i%2 == 0){
	for(int j = 0; j < w-1; ++j){
	  cin >> s;
	  a[t][j][t][j+1] = a[t][j+1][t][j] = (s == 0);
	}
      } else {
	for(int j = 0; j < w; ++j){
	  cin >> s;
	  a[t][j][t+1][j] = a[t+1][j][t][j] = (s == 0);
	}
	++t;
      }
    }

    cout << bfs() << endl;
  }

  return 0;
}