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<vector>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<deque>
#include<map>
#include<bitset>
using namespace std;
typedef long long ll;

#define rep(i, n) for(int i = 0;i < (n);i++)
#define repr(i, n) for(int i = (n);i >= 0;i--)
#define repf(i, m, n) for(int i = (m);i < (n);i++)
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1;} return 0;}
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1;} return 0;}
int dx[] = {0, 1, 0, -1}, dy[] = {-1, 0, 1, 0};
//////////////////////////////////////////////////

// 0: upper
// 1: right
// 2: bottom
// 3: left
int g[35][35][5];
int dist[35][35];
int h, w;
typedef pair<int, int> P;

int bfs (int sy, int sx) {
    queue<P> que;
    que.push(make_pair(sy, sx));
    rep(i,h) rep(j,w) dist[i][j] = -1;
    dist[sy][sx] = 0;
    while(!que.empty()) {
        P cur = que.front(); que.pop();
        int y = cur.first, x = cur.second;
        for(int i = 0; i < 4; ++i) {
            int ny = y + dy[i], nx = x + dx[i];
            if(ny < 0 || nx < 0 || ny >= h || nx >= w) continue;
            // 既に訪れていたらスキップ
            if(dist[ny][nx] != -1) continue;

            if(g[y][x][i] == 0) {
                que.push(make_pair(ny, nx));
                dist[ny][nx] = dist[y][x] + 1;
            }
        }
    }

    int res = dist[h-1][w-1];
    if (res == -1) res = 0;
    else res++;
    return res;
}

int main() {
    while (1) {
        cin >> w >> h;
        if (!w && !h) break;
        rep(i,h+1) rep(j,w+1) rep(k,4) {
            g[i][j][k] = 1;
        }
        int tmp;
        rep(i,h) {
            rep(j,w-1) {
                cin >> tmp;
                g[i][j][1] = tmp;
                g[i][j+1][3] = tmp;
            }
            if (i < h-1) {
                rep(j,w) {
                    cin >> tmp;
                    g[i][j][2] = tmp;
                    g[i+1][j][0] = tmp;
                }
            }
        }

        cout << bfs(0,0) << endl;
    }
    return 0;
}

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

using namespace std;

int main(){

    cin.tie(0);
    ios::sync_with_stdio(false);

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

    int w, h;
    vector<string> wall;
    vector< vector<int> > dist;
    int tx;
    int ty;

    while(cin >> w >> h, w){

        wall.resize((h << 1) - 1);

        cin.ignore();
        for (auto& x : wall)
            getline(cin, x);

        dist.assign(h, vector<int>(w, 0));
        dist[0][0] = 1;

        for(int d = 1; d < w * h; d++)
            for(int y = 0; y < h; y++)
                for(int x = 0; x < w; x++)
                    if(dist[y][x] == d)
                        for(int r = 0; r < 4; r++){
                            tx = x + dx[r];
                            ty = y + dy[r];

                            if(0 > tx || tx >= w || 0 > ty || ty >= h)
                                continue;

                            if(dist[ty][tx] != 0)
                                continue;

                            if (wall[ty + y][tx + x] == '0')
                                dist[ty][tx] = d + 1;
                        }

        cout << dist[h-1][w-1] << endl;

    }

    return 0;

}