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<queue>
using namespace std;

const int INF = 30*30+1;
const int NOTUSE = 400*100;

struct Vec3{
  int x;
  int y;
  int count;
  Vec3(){
    x=0;
    y=0;
    count=1;
  }
};

int main(){

    int w,h;
    while(1){
      cin >> w >> h;
      if(w==0&&h==0){
        break;
      }
      char table[w][h];
      int counttable[w][h];
      bool hwall[w][h],wwall[w][h];
      int input;

      for(int i=0;i<w;i++){
        for(int j=0;j<h;j++){
          table[i][j] = '*';
          counttable[i][j] = INF;
          wwall[i][j] = true;
          hwall[i][j] = true;
        }
      }

      for(int i=0;i<h;i++){

        for(int j=0;j<w-1;j++){
          cin >> input;
          if(input==1){
            hwall[j][i] = false;
          }
        }
        if(i==h-1){
          break;
        }
        for(int j=0;j<w;j++){
          cin >> input;
          if(input==1){
            wwall[j][i] = false;
          }
        }
      }

      queue<Vec3> q;

      Vec3 vec,tmp;
      q.push(vec);
      while(!q.empty()){
        vec = q.front();
        q.pop();

        if(table[vec.x][vec.y]=='.'){
          continue;
        }

        table[vec.x][vec.y]='.';



        if(counttable[vec.x][vec.y] > vec.count){
          counttable[vec.x][vec.y] = vec.count;
        }

        vec.count += 1;
        tmp = vec;
        if(vec.x > 0 && hwall[vec.x-1][vec.y]){
          tmp.x = vec.x - 1;
          tmp.y = vec.y;
          q.push(tmp);
          tmp = vec;
        }

        if(vec.x < w-1 && hwall[vec.x][vec.y]){
          tmp.x = vec.x + 1;
          tmp.y = vec.y;
          q.push(tmp);
          tmp = vec;
        }

        if(vec.y < h-1 && wwall[vec.x][vec.y]){
          tmp.x = vec.x;
          tmp.y = vec.y + 1;
          q.push(tmp);
          tmp = vec;
        }

        if(vec.y > 0 && wwall[vec.x][vec.y-1]){
          tmp.x = vec.x;
          tmp.y = vec.y - 1;
          q.push(tmp);
          tmp = vec;
        }


      }


      if(counttable[w-1][h-1] == INF){
        counttable[w-1][h-1] = -1;
      }
      cout << counttable[w-1][h-1] << endl;

    }




    return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;

static const int inf = 1000;

struct node{
  int x;
  int y;
};



int hor[999][999] = {{}};
int vir[999][999] = {{}};
int pass[999][999] = {{}};
int d[999][999] = {{}};
int h,w;
node locate;
node u,t;

void bfs(int r,int s){

  queue <node> q;
 

  locate.y = r;
  locate.x = s;

  // cout << "lx = " << locate.x << ' ' << "ly = " << locate.y << endl;

  q.push(locate);

  d[0][0] = 1;

  while(!q.empty()){
    u = q.front(); q.pop();
    if(hor[u.y][u.x] != 1 && u.y < h - 1){
      d[u.y + 1][u.x] = d[u.y][u.x] + 1;
      t.x = u.x;
      t.y = u.y + 1; 
      q.push(t);
     
    }
    if(vir[u.y][u.x] != 1 && u.x < w - 1){
      d[u.y][u.x + 1] = d[u.y][u.x] + 1;
      t.y = u.y;
      t.x = u.x + 1;
      q.push(t);
    }

    if((hor[u.y - 1][u.x] != 1) &&( u.y > 0 )&& (( vir[u.y][u.x] = 1) ||( hor[u.y][u.x] == 1))){
      d[u.y - 1][u.x] = d[u.y][u.x] + 1;
      t.x = u.x;
      t.y = u.y - 1; 
      q.push(t);
     
    }

    if((vir[u.y][u.x - 1] != 1) &&( u.x > 0 ) && (( vir[u.y][u.x] = 1) ||( hor[u.y][u.x] == 1))){
      d[u.y][u.x - 1] = d[u.y][u.x] + 1;
      t.y = u.y;
      t.x = u.x - 1;
      q.push(t);
    }

    //   cout << "x = " << u.x << ' ' << "y = " << u.y << endl;
     if(u.x == w - 1 && u.y == h - 1) break;
  
  }





}


int main(){

  cin >> w >> h;

  for(int i =0;i < h - 1;i++){
    for(int j = 0;j < w - 1;j++) cin >> vir[i][j];
    for(int j = 0;j < w ;j++) cin >> hor[i][j];
  }

   for(int j = 0;j < w - 1;j++) cin >> vir[h - 1][j];


   bfs(0,0);

   cout << d[h - 1][w - 1] << endl;

}