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 <bits/stdc++.h>
using namespace std;
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
#define REP(i,n) for(int i=0;i<n;i++)
#define FOR(i,n1,n2) for(int i=n1;i<n2;i++)
#define speed_up    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

typedef long long int ll;
typedef pair<ll,ll> Pi;
const int INF=(ll)(1LL<<31)-1;
const ll INFl=(ll)9223372036854775807;
const int MAX=10000;
const ll MOD=(ll)1e9+7;
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b){return a/gcd(a, b)*b;}
//int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val){
    std::fill( (T*)array, (T*)(array+N), val );
}

int w,h;

int ver[35][35];int hor[35][35];

int maze[35][35];

int main(){
	while(1){
		cin>>w>>h;
		if(w==0&&h==0)break;
		for(int i=0;i<35;i++){
			for(int j=0;j<35;j++){
				maze[i][j]=-1;
			}
		}
		for(int i=0;i<2*h-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];
				}
			}
		}
		
		maze[0][0]=0;
		queue<pair<int,int> > QQ;
		QQ.push(make_pair(0,0));
		while(QQ.size()){
			pair<int,int> q=QQ.front();QQ.pop();
			if(q.first<h-1&&maze[q.first+1][q.second]==-1&&hor[q.first][q.second]==0){
				maze[q.first+1][q.second]=maze[q.first][q.second]+1;
				QQ.push(make_pair(q.first+1,q.second));
			}
			if(q.first>0&&maze[q.first-1][q.second]==-1&&hor[q.first-1][q.second]==0){
				maze[q.first-1][q.second]=maze[q.first][q.second]+1;
				QQ.push(make_pair(q.first-1,q.second));
			}
			if(q.second<w-1&&maze[q.first][q.second+1]==-1&&ver[q.first][q.second]==0){
				maze[q.first][q.second+1]=maze[q.first][q.second]+1;
				QQ.push(make_pair(q.first,q.second+1));
			}
			if(q.second>0&&maze[q.first][q.second-1]==-1&&ver[q.first][q.second-1]==0){
				maze[q.first][q.second-1]=maze[q.first][q.second]+1;
				QQ.push(make_pair(q.first,q.second-1));
			}
		}
		
		/*REP(i,h){
			REP(j,w){
				printf("%4d",maze[i][j]);
			}
			printf("\n");
		}*/
		
		cout<<maze[h-1][w-1]+1<<endl;
		
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
int main(){
	int w,h;
	while(cin>>w>>h){
		if(w==0&&h==0) break;
		int a[h+1][w+1],b[h+1][w+1];
		for(int i=1;i<=h-1;i++){
			for(int j=1;j<=w-1;j++){
				cin>>a[i][j];
			}
			for(int j=1;j<=w;j++){
				cin>>b[i][j];
			}
		}
		for(int i=1;i<=w-1;i++){
			cin>>a[h][i];
		}
		for(int i=0;i<=h;i++){
			a[i][0]=1;
			a[i][w]=1;
		}
		for(int i=0;i<=w;i++){
			b[0][i]=1;
			b[h][i]=1;
		}
		int door[h+1][w+1][4];
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				door[i][j][0]=b[i-1][j];
				door[i][j][1]=a[i][j];
				door[i][j][2]=b[i][j];
				door[i][j][3]=a[i][j-1];
			}
		}
		int map[h+1][w+1];
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				map[i][j]=0;
			}
		}
		map[1][1]=1;
		int ct=1,kai=0;
		while(map[h][w]==0&&ct>0){
			kai++;
			ct=0;
			for(int i=1;i<=h;i++){
				for(int j=1;j<=w;j++){
					if(map[i][j]==kai){
						if(door[i][j][0]==0&&map[i-1][j]==0){
							map[i-1][j]=kai+1;
							ct++;
						}
						if(door[i][j][1]==0&&map[i][j+1]==0){
							map[i][j+1]=kai+1;
							ct++;
						}
						if(door[i][j][2]==0&&map[i+1][j]==0){
							map[i+1][j]=kai+1;
							ct++;
						}
						if(door[i][j][3]==0&&map[i][j-1]==0){
							map[i][j-1]=kai+1;
							ct++;
						}
					}
				}
			}
		}
		if(ct==0){
			cout<<0<<endl;
		}
		else{
			cout<<map[h][w]<<endl;
		}
	}
    return 0;
}