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 <fstream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <algorithm>
#include <complex>
#include <array>
#include <iomanip>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define FOR(i,a,b) for(int i=a; i<=b; ++i)
#define FORR(i,a,b) for (int i=a; i>=b; --i)
#define ALL(c) (c).begin(), (c).end()

typedef long long ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef vector<long double> VD;
typedef vector<VI> VVI;
typedef vector<VL> VVL;
typedef vector<VD> VVD;
typedef pair<int,int> P;
typedef pair<ll,ll> PL;

template<typename T> void chmin(T &a, T b) { if (a > b) a = b; }
template<typename T> void chmax(T &a, T b) { if (a < b) a = b; }

int in() { int x; scanf("%d", &x); return x; }
ll lin() { ll x; scanf("%lld", &x); return x; }
#define INF 1LL<<60

int main() {
    while(true) {
        int W, H;
        cin >> W >> H;
        if(W == 0 && H == 0) break;
        vector< vector<vector<P> > > map(H, vector< vector<P> >(W, vector<P>()));
        REP(i, H ) {
            if(i > 0) {
                REP(j, W) {
                    int w;
                    cin >> w;
                    if(w == 0){
                        map[i][j].push_back(make_pair(i-1, j));
                        map[i-1][j].push_back(make_pair(i, j));
                    }
                }
            }

            REP(j, W-1) {
                int w;
                cin >> w;
                if(w == 0) {
                    map[i][j].push_back(make_pair(i, j+1));
                    map[i][j+1].push_back(make_pair(i, j));
                }
            }
        }

        queue<P> que;
        que.push(make_pair(0, 0));
        vector< vector<int> > dist(H, vector<int>(W, 0));
        dist[0][0] = 1;

        while(!que.empty()) {
            P cur = que.front();
            que.pop();

            for(P next: map[cur.first][cur.second]) {
                if(dist[next.first][next.second] == 0) {
                    dist[next.first][next.second] = dist[cur.first][cur.second] + 1;
                    que.push(next);
                }
            }
        }

        cout << dist[H-1][W-1] << endl;
    }
    return 0;
}

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

class direction{
public:
	int x, y, turn;
	direction(int newx, int newy){
		x = newx;
		y = newy;
	}
};

int main()
{
	int w, h, wall[31][31][4], gone[31][31], turn[31][31], x, y, t, input, before;
	char str[31];
	while (cin >> w >> h, (w || h)){
		//初期化
		for (int i = 0; i < 31; i++){
			for (int j = 0; j < 31; j++){
				for (int k = 0; k < 4; k++){
					wall[i][j][k] = -1;
				}
				gone[i][j] = 0;
				turn[i][j] = -1;
			}
		}
		//外枠
		for (int i = 0; i < w; i++){
			wall[i][0][0] = 1; //上辺
			wall[i][h - 1][2] = 1; //下辺
		}
		for (int i = 0; i < h; i++){
			wall[0][i][1] = 1; //左辺
			wall[w - 1][i][3] = 1; //右辺
		}

		//入力による壁の設定
		for (int i = 0; i < h; i++){
			for (int j = 0; j < w - 1; j++){
				cin >> input;
				wall[j][i][3] = input; //右に行けるか
				wall[j + 1][i][1] = input; //左に行けるか
			}
			if (i < h - 1){
				for (int j = 0; j < w; j++){
					cin >> input;
					wall[j][i][2] = input; //下に行けるか
					if (i < h - 1)
						wall[j][i + 1][0] = input; //上に行けるか
				}
			}
		}

		queue<direction> q;
		direction d = direction(0, 0);
		turn[0][0] = 1;
		gone[0][0] = 1;
		q.push(d);
		while (gone[w - 1][h - 1] != 1 && q.size()>0){
			x = q.front().x;
			y = q.front().y;
			t = turn[x][y];
			if (wall[x][y][0] == 0 && gone[x][y - 1] == 0){
				direction d = direction(x, y - 1);
				q.push(d);
				gone[x][y - 1] = 1;
				turn[x][y - 1] = t + 1;
			}
			if (wall[x][y][1] == 0 && gone[x - 1][y] == 0){
				direction d = direction(x - 1, y);
				q.push(d);
				gone[x - 1][y] = 1;
				turn[x - 1][y] = t + 1;
			}
			if (wall[x][y][2] == 0 && gone[x][y + 1] == 0){
				direction d = direction(x, y + 1);
				q.push(d);
				gone[x][y + 1] = 1;
				turn[x][y + 1] = t + 1;
			}
			if (wall[x][y][3] == 0 && gone[x + 1][y] == 0){
				direction d = direction(x + 1, y);
				q.push(d);
				gone[x + 1][y] = 1;
				turn[x + 1][y] = t + 1;
			}
			q.pop();
		}
		if (turn[w - 1][h - 1] == -1)
			cout << 0 << endl;
		else
			cout << turn[w - 1][h - 1] << endl;
	}
	return 0;
}