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 <algorithm>
#include <numeric>
#include <map>
#include <vector>
#include <iostream>
#include <queue>

using namespace std;

#define REP(i,n) for(int i=0;i<n;i++)


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

int INF=1<<28;
int main() {
	while (true) {
		int W,H;cin >> W >> H;if(W==0 && H==0)break;

		vector<vector<vector<bool>>> wall(H,vector<vector<bool>>(W,vector<bool>(4)));

		REP(inpy,2*H-1){
			int y=inpy/2;
			if(inpy%2==0){
				REP(x,W-1){
					int b;cin >> b;
					wall[y][x][0]=b;
					if(x-1>=0)wall[y][x-1][2]=b;
				}
			}else{
				REP(x,W){
					int b;cin >>b;
					wall[y][x][1]=b;
					if(x+1<W)wall[y][x+1][3]=b;
				}
			}
		}

		priority_queue<pair<int,pair<int,int>>,vector<pair<int,pair<int,int>>>,greater<pair<int,pair<int,int>>>> que;
		que.push(make_pair(0,make_pair(0,0)));
		vector<vector<int>> ds(H,vector<int>(W,INF));ds[0][0]=0;

		vector<vector<bool>> passed(H,vector<bool>(W));
		while(!que.empty()){
			pair<int,pair<int,int>> p=que.top();que.pop();
			int y=p.second.first,x=p.second.second;
			if(passed[y][x])continue;
			passed[y][x]=true;
			REP(d,4)if(!wall[y][x][d]){	
				
				int ny=y+dy[d],nx=x+dx[d];			
				if(0<=nx && nx < W && 0 <= ny && ny < H){
					if(ds[ny][nx]>ds[y][x]+1){
						que.push(make_pair(p.first+1,make_pair(ny,nx)));
						ds[ny][nx]=ds[y][x]+1;
					}
				}
			}
		}
		if(ds[H-1][W-1]!=INF)cout << ds[H-1][W-1]+1<<endl;
		else cout << 0 <<endl;
	}
}

C++: #include<cstdio>
#include<cstdlib>
#include<iostream>
#include<string>
#include<map>
#include<queue>
#include<vector>
#include<algorithm>
#include<climits>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

using namespace std;

const int dx[2] = {1, -1};
const int dy[2] = {0, -1};
int x_w[32][32];
int y_w[32][32];
int dist[32][32];

void bfs(int w, int h){
  pair<int, int> p,tmp;
  queue<pair<int, int> > q;

  REP(i,32)
  REP(j,32)
  dist[i][j] = INT_MAX;

  p.first = p.second = 1;
  dist[1][1] = 1;
  q.push(p);

  while(!q.empty()){
    p = q.front();
    q.pop();

    REP(i,2){
      if(x_w[p.first + dy[i]][p.second -1] == 0 && dist[p.first + dx[i]][p.second] == INT_MAX){
        dist[p.first + dx[i]][p.second] = dist[p.first][p.second]+1;
        tmp.first = p.first + dx[i];
        tmp.second = p.second;
        q.push(tmp);
      }
      if(y_w[p.first -1][p.second + dy[i]] == 0 && dist[p.first][p.second + dx[i]] == INT_MAX){
        dist[p.first][p.second + dx[i]] = dist[p.first][p.second]+1;
        tmp.first = p.first;
        tmp.second = p.second + dx[i];
        q.push(tmp);
      }
    }
  }
}

int main(){
  int w,h;

  while(true){
    cin >> w >> h;
    if(w == 0 && h == 0) break;

    REP(i,h){
      REP(j,w+1){
        if(j == 0 || j == w) y_w[i][j] = 1;
        else cin >> y_w[i][j];
      }
      if(i == h-1) break;
      REP(j,w){
        cin >> x_w[i+1][j];
      }
    }
    REP(i,w){
      x_w[0][i] = 1;
      x_w[h][i] = 1;
    }

    bfs(w,h);
    if(dist[h][w] == INT_MAX) cout << 0 << endl;
    else cout << dist[h][w] << endl;

  }
  return 0;
}