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<queue>
#include<utility>
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define mp make_pair
#define INF (1 << 30)
using namespace std;
typedef pair<int, int> cood;

int tate[33][33], yoko[33][33];
int check[33][33];

void solve(int w, int h) {
    int idx = 0;
    for (int i = 0; i < 2 * h - 1; i++) {
        if (i % 2 == 0) {
            for (int j = 0; j < w - 1; j++) {
                cin >> tate[idx][j];
            }
        }
        else {
            for (int j = 0; j < w; j++) {
                cin >> yoko[idx][j];
            }
            idx++;
        }
    }
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) check[i][j] = WHITE;
    }
    queue<pair<cood, int> > Q;
    int dh[4] = {0, 1, 0, -1}, dw[4] = {-1, 0, 1, 0};
    cood now_cood = mp(0, 0);
    int min_dist = INF;
    Q.push(mp(now_cood, 1));
    check[0][0] = GRAY;
    
    while (! Q.empty()) {
        pair<cood, int> now_info = Q.front();
        now_cood = now_info.first;
        Q.pop();
        check[now_cood.first][now_cood.second] = BLACK;
        if (now_cood.first == h - 1 && now_cood.second == w - 1 && min_dist > now_info.second) {
            min_dist = now_info.second;
        }
        for (int i = 0; i < 4; i++) {
            int nh = now_cood.first + dh[i], nw = now_cood.second + dw[i];
            if (nh >= 0 && nh < h && nw >= 0 && nw < w && check[nh][nw] == WHITE) {
                if (i == 0) {
                    if (now_cood.second - 1 >= 0) {
                        if (tate[now_cood.first][now_cood.second - 1] != 1) {
                            Q.push(mp(mp(nh, nw), now_info.second + 1));
                            check[nh][nw] = GRAY;
                        }
                    }
                    else {
                        Q.push(mp(mp(nh, nw), now_info.second + 1));
                        check[nh][nw] = GRAY;
                    }
                }
                else if (i == 1) {
                    if (now_cood.first < h - 1) {
                        if (yoko[now_cood.first][now_cood.second] != 1) {
                            Q.push(mp(mp(nh, nw), now_info.second + 1));
                            check[nh][nw] = GRAY;
                        }
                    }
                    else {
                        Q.push(mp(mp(nh, nw), now_info.second + 1));
                        check[nh][nw] = GRAY;
                    }
                }
                else if (i == 2) {
                    if (now_cood.second < w - 1) {
                        if (tate[now_cood.first][now_cood.second] != 1) {
                            Q.push(mp(mp(nh, nw), now_info.second + 1));
                            check[nh][nw] = GRAY;
                        }
                    }
                    else {
                        Q.push(mp(mp(nh, nw), now_info.second + 1));
                        check[nh][nw] = GRAY;
                    }
                }
                else {
                    if (now_cood.first - 1 >= 0) {
                        if (yoko[now_cood.first - 1][now_cood.second] != 1) {
                            Q.push(mp(mp(nh, nw), now_info.second + 1));
                            check[nh][nw] = GRAY;
                        }
                    }
                    else {
                        Q.push(mp(mp(nh, nw), now_info.second + 1));
                        check[nh][nw] = GRAY;
                    }
                }
            }
        }
    }
    if (min_dist == INF) cout << 0 << endl;
    else cout << min_dist << endl;
    return;
}

int main() {
    int w, h;
    while (1) {
        cin >> w >> h;
        if (w == 0 && h == 0) {
            break;
        }
        else solve(w, h);
    }
    return 0;
}