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<cmath>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<cstring>
#include<queue>

using namespace std;

#define INF 999999999

vector<pair<int, int> > rin[32][32];
int d[32][32];

queue<pair<int, int> > qu;

void search(pair<int, int> a){
	//cout << a.first << " " << a.second << " " << d[a.first][a.second] << endl;
	pair<int, int> b;
	for(int i=0;i<rin[a.first][a.second].size();i++){
		b.first = rin[a.first][a.second][i].first;
		b.second = rin[a.first][a.second][i].second;
		if(!d[b.first][b.second]){
			qu.push(b);
			d[b.first][b.second] = d[a.first][a.second] + 1;
		}
	}
	qu.pop();
	if(!qu.empty()) search(qu.front());
}

int main(){
	int i, j, k, l, w, h, ins;
	pair<int, int> s;
	while(1){
		cin >> w >> h;
		if(!w)break;
		for(i=0;i<=h+1;i++){
			for(j=0;j<=w+1;j++){
				d[i][j] = 0;
				rin[i][j].clear();
			}
		}
		
		for(i=1;i<=h-1;i++){
			for(j=1;j<=w-1;j++){
				cin >> ins;
				if(!ins){
					rin[i][j].push_back(make_pair(i,j+1));
					rin[i][j+1].push_back(make_pair(i,j));
				}
			}
			for(j=1;j<=w;j++){
				cin >> ins;
				if(!ins){
					rin[i+1][j].push_back(make_pair(i,j));
					rin[i][j].push_back(make_pair(i+1,j));
				}
			}
		}
		for(j=1;j<=w-1;j++){
			cin >> ins;
			if(!ins){
				rin[i][j].push_back(make_pair(i,j+1));
				rin[i][j+1].push_back(make_pair(i,j));
			}
		}
		/*
		for(i=0;i<=h+1;i++){
			for(j=0;j<=w+1;j++){
				cout << i << "," << j << ":";
				for(int z=0;z<rin[i][j].size();z++){
					 cout << rin[i][j][z].first << "," << rin[i][j][z].second << " ";
				}
				cout << endl;
			}
		}
		*/
		//cout << "OK" << endl;
		s.first = 1;
		s.second = 1;
		d[1][1] = 1;
		qu.push(s);
		search(s);
		cout << d[h][w] << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
#define P pair<int, int>
int px[] = { 0, 2, 0, -2 };
int dx[] = { 0, 1, 0, -1 };
int py[] = { 2, 0 ,-2, 0 };
int dy[] = { 1, 0 ,-1, 0 };

int main() {
	int w, h;
	while (cin >> w >> h) {
		if (w == 0 && h == 0)return 0;
		int d[60][60];
		bool m[60][60] = {};
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w - 1; j++) {
				cin >> m[i * 2][2 * j + 1];
			}
			if (i != h - 1) {
				for (int j = 0; j < w; j++) {
					cin >> m[i * 2 + 1][2 * j];
				}
			}
		}

		for (int i = 0; i < 2 * h; i++) {
			for (int j = 0; j < 2 * w; j++) {
				d[i][j] = 1 << 30;
			}
		}
		queue<P> q;
		q.push({ 0,0 });
		d[0][0] = 1;
		while (!q.empty()) {
			P p = q.front();
			q.pop();
			int a = p.first, b = p.second;
			for (int i = 0; i < 4; i++) {
				int rx = a + px[i];
				int tx = a + dx[i];
				int ry = b + py[i];
				int ty = b + dy[i];
				if (0 <= rx && rx < 2 * h && 0 <= ry && ry < 2 * w) {
					if (d[rx][ry] > d[a][b] + 1 && !m[tx][ty]) {
						d[rx][ry] = d[a][b] + 1;
						q.push({ rx, ry });
					}
				}
			}
		}
		cout << (d[2 * h - 2][2 * w - 2] == 1 << 30 ? 0 : d[2 * h - 2][2 * w - 2]) << endl;
	}
	return 0;
}