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<queue>
#include<tuple>
#include<algorithm>

using namespace std;
typedef tuple<int, int> tup;
int vx[4] = { 0,0,1,-1 }, vy[4] = { 1,-1,0,0 };
bool wall[40 * 2 - 1][40];
int d[40][40];

int main() {
	while (1) {
		int h, w;
		cin >> w >> h;
		if (h + w == 0)break;
		for (int i = 0; i < 79; i++)for (int j = 0; j < 39; j++)wall[i][j] = false;
		for (int i = 0; i < 40; i++)for (int j = 0; j < 40; j++)d[i][j] = 0;

		for (int i = 0; i < 2 * h - 1; i++) {
			if (i % 2 == 0) {
				for (int j = 0; j < w - 1; j++) {
					cin >> wall[i][j];
				}
				wall[i][w - 1] = true;
			}
			else {
				for (int j = 0; j < w; j++) {
					cin >> wall[i][j];
				}
			}
		}

		queue<tup> q;
		int ans = 0;
		//左上を(0,0)右下を(h - 1,w - 1)とする座標系でいく
		q.push(make_tuple(0, 0));
		d[0][0] = 1;
		while (q.size()) {
			tup A = q.front(); q.pop();
			int x = std::get<0>(A), y = std::get<1>(A);

			if (x == h - 1 && y == w - 1) {
				std::cout << d[x][y] << endl;
				goto end;
			}
			for (int i = 0; i < 4; i++) {
				//i = 0 ~ 1では左右の動き、2 ~ 3では前後の動き
				int nx = x + vx[i], ny = y + vy[i];
				if (nx < 0 || ny < 0 || nx >= h || ny >= w) continue;

				if (i == 0) {
					if (!d[nx][ny] &&
						!wall[2 * x][y]) {
						tup next;
						next = make_tuple(nx, ny);
						d[nx][ny] = d[x][y] + 1;
						q.push(next);
					}
				}
				else if (i == 1 && y != 0) {
					if (!d[nx][ny] &&
						!wall[2 * x][y - 1]) {
						tup next;
						next = make_tuple(nx, ny);
						d[nx][ny] = d[x][y] + 1;
						q.push(next);
					}
				}
				else if(i == 2){
					if (!d[nx][ny] &&
						!wall[2 * x + 1][y]) {
						tup next;
						next = make_tuple(nx, ny);
						d[nx][ny] = d[x][y] + 1;
						q.push(next);
					}
				}
				else {
					if (x == 0)continue;
					if (!d[nx][ny] &&
						!wall[2 * x - 1][y]) {
						tup next;
						next = make_tuple(nx, ny);
						d[nx][ny] = d[x][y] + 1;
						q.push(next);
					}
				}

			}
		}

		std::cout << 0 << endl;
	end:;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

using pii = pair<int, int>;

constexpr int INF = 1e9;

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

int main() {
    int W, H;
    while(cin >> W >> H, W) {
        vector<vector<int>> wall(2*H-1);
        for(int i=0; i<2*H-1; ++i) {
            int lim = i%2 == 0 ? W-1 : W;
            for(int j=0; j<lim; ++j) {
                int t; cin >> t;
                wall[i].push_back(t);
            }
        }
        vector<vector<int>> d(H, vector<int>(W, INF));
        d[0][0] = 1;
        queue<pii> que;
        que.push(make_pair(0, 0));
        while(!que.empty()) {
            pii p = que.front();
            int y = p.first, x = p.second;
            que.pop();
            int wy[4] = {y*2+1, y*2, y*2-1, y*2};
            int wx[4] = {x, x, x, x-1};
            for(int i=0; i<4; ++i) {
                int ny = y + dy[i];
                int nx = x + dx[i];
                if(ny < 0 || H <= ny || nx < 0 || W <= nx || d[ny][nx] != INF) {
                    continue;
                }
                if(!wall[wy[i]][wx[i]]) {
                    que.push(make_pair(ny, nx));
                    d[ny][nx] = d[y][x] + 1;
                }
            }
        }
        int res = d[H-1][W-1];
        cout << (res == INF ? 0 : res) << endl;
    }
}