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>

#define REP(i, n) for(int i = 0; i < (int) (n); i++)
#define ALL(v) (v).begin(), (v).end()
#define INF 1e9

using namespace std;

struct v{
  int id, cost;
  bool operator<(const v &x)const{
    if(cost < x.cost) return true;
    else return false;
  }
};

int main(){
  int w, h;
  while(cin >> w >> h and w + h){
    vector<vector<int> > Edges(w * h);
    vector<int> costs(w * h);
    priority_queue<v> vertices;
    int clif;
    REP(i, h){
      if(i != 0){
        REP(j, w){
          cin >> clif;
          if(!clif) { Edges[w*(i-1)+j].push_back(w*i+j); Edges[w*i+j].push_back(w*(i-1)+j); }
        }
      }
      REP(j, w-1){
        cin >> clif;
        if(!clif) { Edges[w*i+j].push_back(w*i+j+1); Edges[w*i+j+1].push_back(w*i+j); }
      }
    }
    REP(i, h) REP(j, w) costs[i*w+j] = INF;
    vertices.push({0, 1});
    costs[0] = 1;
    while(!vertices.empty()){
      v target = vertices.top();
      vertices.pop();
      REP(i, Edges[target.id].size()){
        if(costs[Edges[target.id][i]] > costs[target.id] + 1){
          costs[Edges[target.id][i]] = costs[target.id] + 1;
          vertices.push({Edges[target.id][i], costs[target.id] + 1});
        }
      }
    }
    cout << (costs[w*h-1] == INF ? 0 : costs[w*h-1]) << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<queue>

using namespace std;

	int w,h,a,ans;
	bool map[62][62];
	int lap[62][62];
	
struct Node{
	int x,y,d;
	Node(int a,int b,int c){
		x=a;
		y=b;
		d=c;
	}
};
//テ」ツ?禿」ツ?ョテ・ツ、ツ嘉」ツ?ェテ」ツ?ョテ」ツ?ッpushテ」ツつ津、ツクツ?ヲツ仰ャテ」ツ?ァテ」ツつ?」ツつ凝ァツつコ
typedef struct Node node;


int main(){
	//テ・ツ?・テ・ツ環崚」ツ?古ァツ可ケテヲツョツ甘」ツ?ェテ」ツ?ョテ」ツ?ァテ」ツδ榲」ツδε」ツδ療」ツつ津ヲツ仰。テ・ツシツオテ」ツ?凖」ツつ凝」ツ?ィテ」ツ??」ツ??」ツ?凖」ツ?氾」ツ??ヲツ?敕ィツ?ε」ツ?ョテ、ツコツコテ」ツ?ョティツヲツ凝」ツ??
	cin>>w;
	cin>>h;
	
	while(w!=0 || h!=0){
		ans=0;
		for(int lop=0;lop<62;lop++){
			for(int lop2=0;lop2<62;lop2++){
				if(lop==0 || lop==61 || lop2==0 || lop2==61|| lop2==w*2 || lop==h*2){
					map[lop][lop2]=1;
				}else{
					map[lop][lop2]=0;
				}
				lap[lop][lop2]=0;
			}
		}
		//テ」ツδ榲」ツδε」ツδ療」ツ?ョテ・ツ、ツ姪・ツ?エ
		map[0][1]=0;
		map[h*2][w*2-1]=0;
		//テ・ツ?・テ」ツつ甘・ツ渉」テ・ツ?コテ・ツ渉」
		
		for(int lop=0;lop<h*2-1;lop++){
			if(lop%2==0 || lop==0){
				for(int lop2=0;lop2<w-1;lop2++){
					cin>>a;
					if(a==1){
						if(map[lop][lop2*2+2]==0){
							map[lop][lop2*2+2]=1;
						}
						if(map[lop+1][lop2*2+2]==0){
							map[lop+1][lop2*2+2]=1;
						}
						if(map[lop+2][lop2*2+2]==0){
							map[lop+2][lop2*2+2]=1;
						}
					}
				}
			}else{
				for(int lop2=0;lop2<w;lop2++){
					cin>>a;
					if(a==1){
						if(map[lop+1][lop2*2]==0){
							map[lop+1][lop2*2]=1;
						}
						if(map[lop+1][lop2*2+1]==0){
							map[lop+1][lop2*2+1]=1;
						}
						if(map[lop+1][lop2*2+2]==0){
							map[lop+1][lop2*2+2]=1;
						}
					}
				}
			}
		}
		//テ・ツ」ツ?ァツ板淌ヲツ按静」ツ??ヲツ仰。テ・ツシツオテ」ツ?療」ツ?ヲテ」ツ??」ツつ凝」ツ?凝」ツつ嘉・ツ」ツ?」ツつづ、ツクツ?」ツ?、テ」ツ?ォテ」ツ?、テ」ツ?催ッツシツ禿」ツ?、
		//テァツクツヲテ」ツ?ィテヲツィツェテ」ツ?ァテゥツ?催ィツ、ツ?」ツ?凖」ツつ凝・ツ?エテ・ツ青暗」ツ?ッテ・ツ」ツ?・ツ?ェテ・ツ??
		
		bool done[62][62]={0};
		queue<node> q;
		q.push(node(1,1,0));
		//テ・ツ?ィテヲツ篠「テァツエツ「テァツ板ィテ」ツつュテ」ツδ・テ」ツδシテァツ板淌ヲツ按?
		
		while(q.size()!=0){
			node qq=q.front();
			q.pop();
			//テ、ツクツ?」ツ?、テ・ツ?コテ」ツ??テヲツ慊?・ツ按敕」ツ?ッテ・ツスツ禿ァツ?カ 1,1,0
			
			if(done[qq.y][qq.x]==0){
				//テ・ツ」ツ?」ツ?古」ツ?ェテ」ツ??ヲツ卍づ」ツ?ッテゥツ?イテ」ツつ?
				done[qq.y][qq.x]=1;
				//テヲツ按サテ」ツつ嘉」ツ?ェテ」ツ??」ツつ暗」ツ??」ツ?ォテ・ツ」ツ?」ツ?、テ」ツ?湘」ツつ?
				
				if(qq.x==w*2-1 && qq.y==h*2-1){
					ans=(qq.d+2)/2;
					break;
				}
				//テ」ツつエテ」ツδシテ」ツδォテ」ツ?ェテ」ツつ嘉」ツつッテ」ツδェテ」ツつ「
				
				//cout<<"aaaa"<<endl;
				if(map[qq.y][qq.x-1]==0){
					q.push(node(qq.x-1,qq.y,qq.d+1));
				}
				if(map[qq.y-1][qq.x]==0){
					q.push(node(qq.x,qq.y-1,qq.d+1));
				}
				if(map[qq.y][qq.x+1]==0){
					q.push(node(qq.x+1,qq.y,qq.d+1));
				}
				if(map[qq.y+1][qq.x]==0){
					q.push(node(qq.x,qq.y+1,qq.d+1));
				}
			}
			//テ」ツ?ゥテ」ツつ古」ツつづ」ツ?ェテ」ツ??・ツ?エテ・ツ青?テ」ツつ津・ツ?コテ」ツ?療」ツ?ヲテァツオツづ、ツコツ?
		}
		cout<<ans<<endl;
		
		cin>>w;
		cin>>h;
	}
	
	return 0;
}