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 <cstdio>
#include <cstdlib>
#include <string>
#include <vector>
#include <deque>
#include <list>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <cstring>
#include <cctype>
#include <sstream>
#include <set>
#include <map>
#include <queue>
#include <complex>
using namespace std;

int field[30][30];
int hor[30][30];
int ver[30][30];
int result;
int w, h;


int main() {
	while(1) {
		cin >> w >> h;
		if(w==0 && h==0) break;

		for(int i=0; i<h; i++)
			for(int j=0; j<w; j++)
				field[i][j] = 0;

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

		queue<int> q;
		q.push(0);
		q.push(0);
		q.push(1);
		result = 0;

		while(q.size() != 0) {
			int x = q.front();
			q.pop();
			int y = q.front();
			q.pop();
			int cnt = q.front();
			q.pop();

			if(field[y][x] == 1) continue;

			if(x == w-1 && y == h-1) {
				result = cnt;
				break;
			}

			if(y<h-1 && hor[y][x] == 0) {
				q.push(x);
				q.push(y+1);
				q.push(cnt+1);
			}
			if(x<w-1 && ver[y][x] == 0) {
				q.push(x+1);
				q.push(y);
				q.push(cnt+1);
			}
			if(y>0 && hor[y-1][x] == 0) {
				q.push(x);
				q.push(y-1);
				q.push(cnt+1);
			}
			if(x>0 && ver[y][x-1] == 0) {
				q.push(x-1);
				q.push(y);
				q.push(cnt+1);
			}
			field[y][x] = 1;
		}
		cout << result << endl;
	}
	return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <cmath>
#include <ctype.h>
#include <string> 
#include <sstream>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>

using namespace std;
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int meiro[40][40][40][40];
int tesu[40][40];
int issearched[40][40];
int w, h;

void tansaku(int a, int b);

int main()
{
	while(1){
		cin >> w >> h;
		if(w == 0 && h == 0) break;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				tesu[i][j] = 0;
				issearched[i][j] = 0;
			}
		}
		for(int i = 0; i < h - 1; i++){
			for(int j = 0; j < w - 1; j++){
				cin >> meiro[j][i][j + 1][i];
			}
			for(int j = 0; j < w; j++){
				cin >> meiro[j][i][j][i + 1];
			}
		}
		for(int i = 0; i < w - 1; i++){
			cin >> meiro[i][h - 1][i + 1][h - 1];
		}
		tansaku(0, 0);
		cout << tesu[w - 1][h - 1] << endl;
	}
	return 0;
}

void tansaku(int a, int b)
{
	queue<pair<int, int> > qu;
	qu.push(pair<int, int>(a, b));
	tesu[a][b] = 1;
	issearched[a][b] = 1;
	int x, y, next_x, next_y;
	while(1){
		if(qu.empty()) break;
		x = (qu.front()).first;
		y = (qu.front()).second;
		for(int i = 0; i < 4; i++){
			next_x = x + dx[i];
			next_y = y + dy[i];
			if(next_x < 0 || next_x >= w || next_y < 0 || next_y >= h) continue;
			if(issearched[next_x][next_y] == 0 && meiro[x][y][next_x][next_y] == 0){
				issearched[next_x][next_y] = 1;
				tesu[next_x][next_y] = tesu[x][y] + 1;
				qu.push(pair<int, int>(next_x, next_y));
			}
		}
		qu.pop();
	}
	return;
}