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 <cstdio>
#include <queue>

#define int long long
#define dotimes(i, n) for (int i : range(n))

using namespace std;

class range {
  class iterator {
    int i, s;
  public:
    iterator(int i, int s): i(i), s(s) {}
    int& operator*() {
      return i;
    }
    void operator++() {
      i += s;
    }
    bool operator!=(iterator const& that) {
      return i < that.i;
    }
  };
  iterator b, e;
public:
  range(int e): b({0, 1}), e({e, 1}) {}
  range(int b, int e): b({b, 1}), e({e, 1}) {}
  range(int b, int e, int s): b({b, s}), e({e, s}) {}
  iterator begin() {
    return b;
  }
  iterator end() {
    return e;
  }
};

int rint() {
  int n;
  scanf("%lld", &n);
  return n;
}

void wint(int n) {
  printf("%lld\n", n);
}

template<typename T>
inline int size(T container) {
  return static_cast<int>(container.size());
}

template<typename T>
inline bool maxs(T& a, T const& b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

template<typename T>
inline bool mins(T& a, T const& b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

signed main() {
  for (;;) {
    const int w = rint();
    const int h = rint();
    if (!w && !h)
      break;
    bool walls[2*h+1][w+1];
    dotimes(i, w) {
      walls[0][i] = 1;
      walls[2*h][i] = 1;
    }
    walls[0][0] = 0;
    walls[2*h][w-1] = 0;
    dotimes(j, 2 * h - 1)
      if (j % 2) {
        dotimes(i, w)
          walls[j+1][i] = rint();
      } else {
        walls[j+1][0] = 1;
        dotimes(i, w-1)
          walls[j+1][i+1] = rint();
        walls[j+1][w] = 1;
      }
    int sp[h][w] = {};
    queue<pair<int, int>> q;
    q.emplace(0, 0);
    sp[0][0] = 1;
    while (!q.empty()) {
      auto p = q.front();
      q.pop();
      int j = p.first, i = p.second, d = sp[j][i] + 1;
      int ks[4] = {}, dy[4] = {-1, 1, 0, 0}, dx[4] = {0, 0, -1, 1};
      if (!walls[2*j][i])
        ks[0] = 1;
      if (!walls[2*(j+1)][i])
        ks[1] = 1;
      if (!walls[2*j+1][i])
        ks[2] = 1;
      if (!walls[2*j+1][i+1])
        ks[3] = 1;
      dotimes(k, 4)
        if (ks[k]) {
          int y = j + dy[k], x = i + dx[k];
          if (!sp[y][x]) {
            sp[y][x] = d;
            q.emplace(y, x);
          }
        }
    }
    wint(sp[h-1][w-1]);
  }
  return 0;
}

C++: 

#include <iostream>
#include <algorithm>
#include <stdlib.h>
#include <string>
#include <queue>
#include <map>
#include <stack>
using namespace std;
 
int dx[8]={1,-1,0,0,1,1,-1,-1};
int dy[8]={0,0,1,-1,-1,1,-1,1};
 
 
int main() {
int tate,yoko;
while(cin>>yoko>>tate && yoko){
int t[35][35]={0},y[35][35]={0};
for(int i=0;i<2*tate-1;i++){
if(i%2==0){
for(int j=0;j<yoko-1;j++) cin>>y[i/2][j];
}
else{
for(int j=0;j<yoko;j++) cin>>t[i/2][j];
}
}
int su[35][35]={0};
queue<pair<pair<int,int>,int > > qu;
qu.push(make_pair(make_pair(0,0),0));
su[0][0]=1;
int ans;
while(1){
if(qu.size()==0){
ans=-1;
break;
}
pair<pair<int,int>,int > dd=qu.front();
qu.pop();
int t1=dd.first.first,y1=dd.first.second;
if(dd.first.first==tate-1 && dd.first.second==yoko-1){
ans=dd.second;
break;
}
for(int i=0;i<4;i++){
if(0>t1+dx[i] || t1+dx[i]>=tate || 0>y1+dy[i] || y1+dy[i]>=yoko) continue;
if((i==0 && su[t1+dx[i]][y1+dy[i]]==0 && t[t1][y1]==0) ||(i==1 && su[t1+dx[i]][y1+dy[i]]==0 && t[t1+dx[i]][y1+dy[i]]==0)||(i==2 && su[t1+dx[i]][y1+dy[i]]==0 && y[t1][y1]==0) || (i==3 && su[t1+dx[i]][y1+dy[i]]==0 && y[t1+dx[i]][y1+dy[i]]==0) ){
qu.push(make_pair(make_pair(t1+dx[i],y1+dy[i]),dd.second+1));
su[t1+dx[i]][y1+dy[i]]=1;
//cout<<t1+dx[i]<<" "<<y1+dy[i]<<" "<<dd.second+2<<endl;
}

}



}

cout<<ans+1<<endl;
}


	return 0;
 
}