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;

int main()
{
    for (;;) {
        int w, h;
        cin >> w >> h;
        if (w == 0 && h == 0)
            break;

        int wall[59][59] = {};
        for (int i = 0; i < 2 * h - 1; ++i) {
            for (int j = (i + 1) % 2; j < 2 * w - 1; j += 2) {
                cin >> wall[j][i];
            }
        }

        int x = 0, y = 0, l = 1, min = 9999;
        queue<int> q;
        int visited[30][30] = {};
        q.push(x);
        q.push(y);
        q.push(l);
        visited[x][y] = 1;
        for (;;) {
            int f = 0;
            x = q.front();
            q.pop();
            y = q.front();
            q.pop();
            l = q.front();
            q.pop();

            if (x == w - 1 && y == h - 1) {
                if (l < min)
                    min = l;
            }

            // right
            if (2 * x + 1 < 2 * w - 1 &&
                    wall[2 * x + 1][2 * y] == 0 && visited[x + 1][y] == 0) {
                q.push(x + 1);
                q.push(y);
                q.push(l + 1);
                visited[x + 1][y] = 1;
                f = 1;
            }
            // down
            if (2 * y + 1 < 2 * h - 1 &&
                    wall[2 * x][2 * y + 1] == 0 && visited[x][y + 1] == 0) {
                q.push(x);
                q.push(y + 1);
                q.push(l + 1);
                visited[x][y + 1] = 1;
                f = 1;
            }
            // left
            if (2 * x - 1 >= 0 &&
                    wall[2 * x - 1][2 * y] == 0 && visited[x - 1][y] == 0) {
                q.push(x - 1);
                q.push(y);
                q.push(l + 1);
                visited[x - 1][y] = 1;
                f = 1;
            }
            // top
            if (2 * y - 1 >= 0 &&
                    wall[2 * x][2 * y - 1] == 0 && visited[x][y - 1] == 0) {
                q.push(x);
                q.push(y - 1);
                q.push(l + 1);
                visited[x][y - 1] = 1;
                f = 1;
            }

            if (f == 0 && q.empty())
                break;
        }

        cout << (min == 9999 ? 0 : min) << endl;
    }

    return 0;
}

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

typedef pair<int,int> P;

int main(){
  int i,j;
  int h,w;
  int lr[100][100],ud[100][100];
  int grid[100][100];  

  while(scanf("%d %d",&w,&h) && (w||h)){
    for(i=0;i<h-1;i++){
      for(j=0;j<w-1;j++)scanf("%d",&lr[i][j]);
      for(j=0;j<w;j++)scanf("%d",&ud[i][j]);
    }
    for(j=0;j<w-1;j++)scanf("%d",&lr[h-1][j]);

    for(i=0;i<h;i++)for(j=0;j<w;j++)grid[i][j] = 0;
    grid[0][0] = 1;

    queue<P> q;
    q.push(P(0,0));

    while(q.size()){
      P p = q.front();q.pop();
      int y = p.first,x = p.second;

      if(y==h-1 && x==w-1)break;
      
      int dy[] = {1,0,-1,0},dx[] = {0,1,0,-1};
      for(int k=0;k<4;k++){
	int sy = y+dy[k], sx = x+dx[k];
	if(sy < 0 || sx < 0 || h-1 < sy || w-1 < sx)continue;
	if(k==0 && ud[y][x])continue;
	if(k==1 && lr[y][x])continue;
	if(k==2 && ud[sy][sx])continue;
	if(k==3 && lr[sy][sx])continue;
	if(grid[sy][sx] > 0)continue;
	grid[sy][sx] = grid[y][x] + 1;
	q.push(P(sy,sx));
      }
    }

    printf("%d\n",grid[h-1][w-1]);
  }
}