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++: /*
    Problem 32
    https://onlinejudge.u-aizu.ac.jp/problems/1166
*/
#include <bits/stdc++.h>
using namespace std;
/* typedef */
typedef long long ll;
typedef pair<int, int> pii;
/* constant */
const int INF = 1 << 30;
const ll LINF = 1LL << 50;
const int NIL = -1;
const int MAX = 10000;
const int mod = 1000000007;
const double pi = 3.141592653589;
/* global variables */
vector<int> dx{0, 0, 1, -1}, dy{1, -1, 0, 0};
/* function */
void solve(int h, int w) {
    int H = 2*h - 1, W = 2*w - 1;
    vector<vector<int>> G(H, vector<int>(W, 0));
    for (int i = 0; i < H; i++)
        for (int j = (i%2 == 0); j < W; j+=2)
            cin >> G[i][j];
    int sx = 0, sy = 0, gx = H-1, gy = W - 1;
    queue<pii> q;
    vector<vector<int>> dist(H, vector<int>(W, 0));
    dist[sx][sy] = 1;
    q.emplace(sx, sy);

    while (!q.empty()) {
        pii p = q.front();
        q.pop();
        int x = p.first, y = p.second;
        for (int i = 0; i < dx.size(); i++) {
            int nx = x + dx[i], ny = y + dy[i];
            int nnx = x + 2 * dx[i], nny = y + 2 * dy[i];
            if (nx < 0 || H <= nx || ny < 0 || W <= ny) continue;
            if (G[nx][ny] || G[nnx][nny]) continue;
            if (dist[nnx][nny] != 0) continue;
            dist[nnx][nny] = dist[x][y] + 1;
            q.emplace(nnx, nny);
        }
    }
    cout << dist[gx][gy] << '\n';
}
/* main */
int main(){
    int h, w;
    while (1) {
        cin >> w >> h;
        if (w == 0) return 0;
        solve(h, w);
    }
}

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

#define MAX 30
#define BLANK 0
#define UP 1
#define RIGHT 2
#define DOWN 4
#define LEFT 8
#define VISITED 16

struct data{int y,x,distance;};

int main()
{
  int field[MAX][MAX];
  int direction[4]={UP,RIGHT,DOWN,LEFT};
  int dy[4]={-1,0,1,0};
  int dx[4]={0,1,0,-1};

  int w,h,a,ans;
  int i,j;

  while(cin>>w>>h,w|h){
    queue<data> q;
    for(i=0;i<MAX;i++)for(j=0;j<MAX;j++)field[i][j]=BLANK;
    for(i=0;i<h;i++){
      field[i][0]^=LEFT;
      field[i][w-1]^=RIGHT;
    }
    for(j=0;j<h;j++){
      field[0][j]^=UP;
      field[h-1][j]^=DOWN;
    }
    for(i=0;i<2*h-1;i++){
      for(j=0;~i&1 && j<w-1;j++){
	cin>>a;
	if(!a)continue;
	field[i/2][j]^=RIGHT;
	field[i/2][j+1]^=LEFT;
      }
      for(j=0;i&1 && (j<w);j++){
	cin>>a;
	if(!a)continue;
	field[i/2][j]^=DOWN;
	field[i/2+1][j]^=UP;
      }
    }
    ans=0;
    data d={0,0,1};
    field[0][0]^=VISITED;
    q.push(d);
    while(!q.empty()){
      data d=q.front(),dd;
      q.pop();
      if(d.y==h-1 && d.x==w-1){
	ans=d.distance;
	break;
      }
      for(i=0;i<4;i++){
	if(field[d.y][d.x]&direction[i])continue;
	dd.x = d.x+dx[i];
	dd.y = d.y+dy[i];
	dd.distance = d.distance+1;
	if(dd.x<0 || w<=dd.x || dd.y<0 || h<=dd.y)continue;
	if(field[dd.y][dd.x]&VISITED)continue;
	field[dd.y][dd.x]^=VISITED;
	q.push(dd);
      }
    }
    cout<<ans<<endl;
  }
}