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 <vector>
#include <map>
#include <queue>
#include <utility>
#include <cmath>
#include <string.h>

using namespace std;

int main(int argc, char* argv[]) {
  vector<int> rets;
  while (true) {
    int w, h;
    cin >> w >> h;

    if (w == 0 && h == 0)
      break;

    map<pair<int, int>, vector<pair<int, int> > > m;
    for (int i = 0; i < h; ++i) {
      int horizon[w - 1];
      for (int j = 0; j < w - 1; ++j)
        cin >> horizon[j];

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

      for (int j = 0; j < w; ++j) {
        pair<int, int> cur = make_pair(i, j);
        int cur_x = j;
        int cur_y = i;

        // check right
        int next_y = cur_y;
        int next_x = cur_x + 1;
        pair<int, int> next = make_pair(next_y, next_x);
        if (next_x < w) {
          if (horizon[cur_x] == 0) {
            m[cur].push_back(next);
            m[next].push_back(cur);
          }
        }

        // check bottom
        next_y = cur_y + 1;
        next_x = cur_x;
        next = make_pair(next_y, next_x);
        if (next_y < h) {
          if (vertical[cur_x] == 0) {
            m[cur].push_back(next);
            m[next].push_back(cur);
          }
        }
      }
    }

    int d[h][w];
    memset(d, -1, sizeof(int) * h * w);
    d[0][0] = 0;

    queue<pair<int, int> > q;
    q.push(make_pair(0, 0));
    while (!q.empty()) {
      pair<int, int> cur = q.front();
      q.pop();
      int cur_x = cur.second;
      int cur_y = cur.first;
      for (int i = 0; i < m[cur].size(); ++i) {
        pair<int, int> next = m[cur][i];
        int next_x = next.second;
        int next_y = next.first;
        if (d[next_y][next_x] == -1) {
          d[next_y][next_x] = d[cur_y][cur_x] + 1;
          q.push(next);
        }
      }
    }

    if (d[h - 1][w - 1] == -1)
      rets.push_back(0);
    else
      rets.push_back(d[h - 1][w - 1] + 1);
  }

  for (int i = 0; i < rets.size(); ++i)
    cout << rets[i] << endl;

  return 0;
}

C++: // 迷図と命ず
// 所要時間 分
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i=0; i<(n); ++i)
#define REP(i, d, n) for(int i=(d); i<(n); ++i)
#define all(v) v.begin(), v.end()

int main() {

    int w, h;
    while(true){
        cin >> w >> h;
        if(w == 0 && h == 0){
            break;
        }
        vector<vector<int> > graph(h, vector<int>(w));
        vector<vector<int> > tate(h, vector<int>(w-1));
        vector<vector<int> > yoko(h-1, vector<int>(w));
        rep(i, w-1){
            cin >> tate[0][i];
        }
        rep(k, h-1){
            rep(i, w){
                cin >> yoko[k][i];
            }
            rep(i, w-1){
                cin >> tate[k+1][i];
            }
        }

        queue<pair<int, int> > q;
        vector<vector<int> > dis(h, vector<int>(w, -1));
        q.push({0, 0});
        dis[0][0] = 1;
        const int dy[] = {0, 1, 0, -1};
        const int dx[] = {1, 0, -1, 0};
        while(!q.empty()){
            int y = q.front().first;
            int x = q.front().second;
            q.pop();
            rep(i, 4){
                int ny = y + dy[i];
                int nx = x + dx[i];
                if(ny < 0 || nx < 0 || ny >= h || nx >= w){
                    continue;
                }
                if(abs(ny - y) == 1 && yoko[min(y, ny)][nx] == 1){
                    continue;
                }
                if(abs(nx - x) == 1 && tate[ny][min(x, nx)] == 1){
                    continue;
                }
                if(dis[ny][nx] == -1){
                    dis[ny][nx] = dis[y][x] + 1;
                    q.push({ny, nx});
                }
            }
        }        
        if(dis[h-1][w-1] != -1){
            cout << dis[h-1][w-1] << endl;
        }
        else{
            cout << 0 << endl;
        }
    }

    return 0;
}