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"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
template<class T>
using Table = vector<vector<T>>;
const ld eps=1e-9;

//// < "D:\D_Download\Visual Studio 2015\Projects\programing_contest_c++\Debug\a.txt"


const int dx[4] = { -1,0,1,0 };
const int dy[4] = { 0,1,0,-1 };
struct aa {
	int x;
	int y;
	int time;
};
int main() {
	while (1) {
		int W, H; cin >> W >> H;
		if (!W)break;
		vector<vector<vector<int>>>field(H, vector<vector<int>>(W,vector<int>(4)));
		for (int y = 0; y < 2*H-1; ++y) {
			if (y % 2) {
				for (int x = 0; x < W; ++x) {
					int a; cin >> a;
					if (a) {
						field[y / 2][x][1] = true;
						field[y / 2 + 1][x][3] = true;
					}
				}
			}
			else {
				for (int x = 0; x < W-1; ++x) {
					int a; cin >> a;
					if (a) {
						field[y / 2][x][2] = true;
						field[y / 2][x + 1][0] = true;
						
					}
				}
			}
		}
		vector<vector<int>>memo(H, vector<int>(W, 1e8));
		queue<aa>que; que.push(aa{ 0,0,0 });
		memo[0][0] = 0;
		int ans = 0;
		while (!que.empty()) {
			aa atop= que.front();
			
			que.pop();
			for (int way = 0; way < 4; ++way) {
				const int newx = atop.x + dx[way];
				const int newy = atop.y + dy[way];
				if (newx >= 0 && newx < W&&newy >= 0 && newy < H&&!field[atop.y][atop.x][way]) {
					if (memo[newy][newx] > atop.time + 1) {
						memo[newy][newx] = atop.time + 1;
						que.push(aa{ newx,newy,atop.time + 1 });
					}
				}
			}
		}
		if (memo[H - 1][W - 1]<1e6) {
			cout << memo[H - 1][W - 1]+1 << endl;
		}
		else {
			cout << 0 << endl;
		}
	}
	return 0;
}

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

int main(){
	int dw[]={0,1,-1,0};
	int dh[]={1,0,0,-1};
	int w,h;
	while(cin>>w>>h,w){
		vector<vector<int>> wallw(w-1,vector<int>(h));
		vector<vector<int>> wallh(w,vector<int>(h-1));
		for(int i=0;i<h;i++){
			for(int j=0;j<w-1;j++)
				cin>>wallw[j][i];
			if(i==h-1)
					break;
			for(int j=0;j<w;j++)
				cin>>wallh[j][i];
		}
		vector<vector<int> > been(w,vector<int>(h,0));
		queue<pair<pair<int,int> ,int> > q;
		q.push(make_pair(make_pair(0,0),0));
		while(!q.empty()){
			pair<int,int> p=q.front().first;
			int turn =q.front().second;
			if(p.first==w-1 && p.second==h-1){
				cout<<turn+1<<endl;
				break;
			}
			q.pop();
			been[p.first][p.second]=1;
			for(int i=0;i<4;i++){
					if(0<=p.first+dw[i] && p.first+dw[i]<w && 0<=p.second+dh[i] && p.second+dh[i]<h){
						if((((i==0 || i==3)&&wallh[p.first][p.second+(dh[i]-1)/2]==0) ||( (i==1|| i==2)&&wallw[p.first+(dw[i]-1)/2][p.second]==0) )&& !been[p.first+dw[i]][p.second+dh[i]])
						q.push(make_pair(make_pair(p.first+dw[i],p.second+dh[i]),turn+1));
					}
				

			}


		}
		if(q.empty())
			cout<<0<<endl;

	}


}