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 <queue>
#include <iostream>
#include <vector>
#include <cstdio>
#include <cstring>
#include <cstdlib>
using namespace std;

typedef pair<int,int> PA;

class Node{
public:
  int cost;
  PA p;
  
  //コストラクタ
  Node(int cost, PA p):cost(cost), p(p){
    
  }
  
  bool operator < (const Node &o)const{
    return cost  > o.cost;
  }

};

typedef priority_queue<Node> PQ;

int field[80][80];
int w,h;

void show(){
  for(int i = 0 ; i < h*2-1; i++){
    for(int j = 0; j < w*2-1; j++){
      cout << field[i][j] << " ";
    }
    cout << endl;
  }

}

int dx[] = {1,0,-1,0};
int dy[] = {0,1,0,-1};

bool closed[80][80];
int dijkstra(){
  PQ pq;
  pq.push(Node(1,PA(0,0)));
  for(int i = 0 ; i < 80; i++)for(int j = 0 ; j < 80; j++)closed[i][j] = false;

  while(!pq.empty()){
    Node current = pq.top();pq.pop();

    if(closed[current.p.second][current.p.first])continue;

    closed[current.p.second][current.p.first] = true;

    //cout << "(" << current.p.first << "," << current.p.second << ")" << current.cost << endl;
    if(current.p.first == w*2-2 && current.p.second == h*2-2)return current.cost;
    for(int i = 0; i < 4; i++){
      int nx = current.p.first + dx[i];
      int ny = current.p.second + dy[i];

      if(nx < 0 || nx >= w*2-1)continue;
      
      if(ny < 0 || ny >= h*2-1)continue;

      if(field[ny][nx] == 1)continue;
	 nx += dx[i];
	 ny += dy[i];
      if(nx < 0 || nx >= w*2-1)continue;

      if(ny < 0 || ny >= h*2-1)continue;

      if(field[ny][nx] == 1)continue;

	 
      pq.push(Node( current.cost + 1, PA(nx,ny) ));
    }
  }
  return 0;
}

int main(){

  while(cin >> w >> h, w || h){
    for(int i = 0 ; i < h; i++)for(int j = 0; j < w; j++)field[i][j] = 0;
    for(int i = 0; i < h*2-1; i++){
      if(i%2){
	for(int j = 0; j < w; j++){
	  cin >> field[i][j*2];
	}
      }else{
	for(int j = 0; j < w-1; j++){
	  cin >> field[i][1+j*2];
	}
      }
    }

    cout << dijkstra() << endl;
  }
}

C++: #include <bits/stdc++.h>
using namespace std;

struct block{

  int tate, yoko, step;

};

struct xy{
  int x, y, step;
};
block maze[31][31];
int ww, hh;
queue<xy> qu;
int xx[4] = {0, 0, 1, -1};
int yy[4] = {-1, 1, 0, 0};
int h, w;
int d[31][31];

void wide(){

  memset(d,0,sizeof(d));
  maze[0][0].step = 1;
  qu.push((xy){0,0,1});
  int x = 0, y = 0;
  d[0][0] = 1;

  while(!qu.empty()){

    xy st;
    st = qu.front();
    qu.pop();

   
    if(st.x+1 >= 0 && st.x+1 < w && st.y >= 0 && st.y < h && d[st.x+1][st.y] == 0 && maze[st.x][st.y].tate == 0){
      qu.push((xy){st.x+1,st.y,st.step+1});
      d[st.x+1][st.y] = st.step + 1;
    }
    if(st.x-1 >= 0 && st.x-1 < w && st.y >= 0 && st.y < h && d[st.x-1][st.y] == 0 && maze[st.x-1][st.y].tate == 0){
      qu.push((xy){st.x-1,st.y,st.step+1});
      d[st.x-1][st.y] =  st.step + 1;
    }
    if(st.x >= 0 && st.x < w && st.y+1 >= 0 && st.y+1 < h && d[st.x][st.y+1] == 0 && maze[st.x][st.y].yoko == 0){
      qu.push((xy){st.x,st.y+1,st.step+1});
      d[st.x][st.y+1] =  st.step + 1;
    }
    if(st.x >= 0 && st.x < w && st.y-1 >= 0 && st.y-1 < h && d[st.x][st.y-1] == 0 && maze[st.x][st.y-1].yoko == 0){
      qu.push((xy){st.x,st.y-1,st.step+1});
      d[st.x][st.y-1] =  st.step + 1;
    }

  }
 cout << d[w-1][h-1] << endl;
 /* for(int i = 0; i < h; i++){
    for(int j = 0; j < w; j++){
      cout << d[j][i] << " ";
    }
    cout << endl;
    }*/

}

int main(){

 
  while(cin >> w >> h && (w || h)){

   

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

     
      for(int j = 0; j < w-1; j++){
	cin >> maze[j][i].tate;
      }

      if(i != h-1){
	for(int t = 0; t < w; t++){
	  cin >> maze[t][i].yoko;
	}
      }
    }
    wide();
  }


}