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 <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)   FOR(i,0,n)
#define pb emplace_back
typedef long long ll;
typedef pair<int,int> pint;

bool used[31][31];
int g[61][31];
const int dx[]={-1,1,0,0},dy[]={0,0,-1,1};
int main(){
    int w,h;
    while(cin>>w>>h,w|h){
        memset(used,0,sizeof(used));
        rep(i,2*h-1){
            if(i%2==0){
                rep(j,w-1) cin>>g[i][j];
            }
            else rep(j,w) cin>>g[i][j];
        }
        queue<pair<pint,int> > q;
        q.push({{0,0},1});
        used[0][0]=true;
        bool flag=false;
        while(!q.empty()){
            pair<pint,int> pi=q.front();q.pop();
            rep(i,4){
                int tx=pi.first.first+dx[i],ty=pi.first.second+dy[i];
                if(tx>=0&&ty>=0&&tx<w&&ty<h&&!used[ty][tx]&&
                (i==0&&g[ty*2][tx]==0||i==1&&g[ty*2][tx-1]==0||
                i==2&&g[ty*2+1][tx]==0||i==3&&g[ty*2-1][tx]==0)){
                    if(tx==w-1&&ty==h-1){
                        cout<<pi.second+1<<endl;
                        flag=true;
                    }
                    q.push({{tx,ty},pi.second+1});
                    used[ty][tx]=true;
                }
                if(flag) break;
            }
            if(flag) break;
        }
        if(!flag) cout<<0<<endl;
    }
    return 0;
}

C++: #include <vector>
#include <iostream>
#include <utility>
#include <algorithm>
#include <string>
#include <deque>
#include <queue>
#include <tuple>
#include <queue>
#include <functional>
#include <cmath>
#include <iomanip>
#include <map>
#include <set>
#include <numeric>
#include <unordered_map>
#include <unordered_set>
#include <complex>
#include <iterator>
#include <array>
#include <memory>
#include <stack>
#define vi vector<int>
#define vvi vector<vector<int> >
#define ll long long int
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
#define ld long double
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,s,n) for(int i=s;i<n;i++)
#define all(in) in.begin(), in.end()
template<class T, class S> void cmin(T &a, const S &b) { if (a > b)a = b; }
template<class T, class S> void cmax(T &a, const S &b) { if (a < b)a = b; }
#define MAX 9999999
using namespace std;
typedef  pair<int,int> pii;
int H,W;
bool inrange(int y,int x){return(0<=x&&x<W&&0<=y&&y<H);}
int dy[]={0,0,1,-1};
int dx[]={1,-1,0,0};
int main(){
    while(cin>>W>>H,H+W){
        vector<vector<int>>graph(31,vector<int>(31,INF));
        vector<vector<int>>un(31);
        vector<vector<int>>ci(31);
        rep(i,H){
            rep(j,W-1){
                int t; cin>>t;
                ci[i].push_back(t);
            }
            if(i==H-1)continue;
            rep(j,W){
                int t; cin>>t;
                un[i].push_back(t);
                
            }
        }
        rep(j,W)un[H-1].push_back(0);
        queue<pii>que;
        que.push(pii(0,0));
        graph[0][0]=1;
        while(!que.empty()){
            pii now=que.front();que.pop();
            rep(i,4){
                int x=now.second+dx[i];
                int y=now.first+dy[i];
                if(!inrange(y,x))continue;
                if(graph[y][x]!=INF)continue;
                if(i==0||i==1){
                    if(i==1){if(ci[now.first][(now.second-1)]==0){que.push(pii(y,x));cmin(graph[y][x],graph[now.first][now.second]+1);}}
                    else {if(ci[now.first][(now.second)]==0){que.push(pii(y,x));cmin(graph[y][x],graph[now.first][now.second]+1);}}
                }else{
                    if(un[(i==3?now.first-1:now.first)][now.second]==0){que.push(pii(y,x));cmin(graph[y][x],graph[now.first][now.second]+1);}
                }
            }
        }
        cout<<(graph[H-1][W-1]==INF?0:graph[H-1][W-1])<<endl;
    }
}