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>
#include<iomanip>

#define INF (1 << 29)
#define x pos.first
#define y pos.second

using namespace std;

typedef pair<int, int> Pos;


struct Path
{
    Pos pos;
    int cost;
};



//?????????
const int dx[2] = {-1, 1};

//?????????
const int dy[2] = {-1, 1};

int main()
{
    int w, h;
    while(cin >> w >> h, (w + h))
    {
        int map_ver[32][32];//???
        int map_hor[32][32];//?¨?
        int min_cost[31][31];

        for(int i = 0; i < h; i++)
        {
            for(int j = 0; j < w; j++)
            {
                min_cost[i][j] = INF;
            }
        }

        //*
        for(int i = 0; i < h; i++)
        {
            for(int j = 0; j < w - 1; j++)
            {
                cin >> map_ver[i][j];
            }
            if(i < h - 1)for(int j = 0; j < w; j++)
            {
                cin >> map_hor[i][j];
            }
        }
        //*/

        queue< Path > path;

        path.push(Path{ Pos(0, 0), 1 });
        min_cost[0][0] = 1;

        //*
        while(!path.empty())
        {
            const Path now = path.front();
            path.pop();

            for(int i = 0; i < 2; i++)
            {
                const int nextCost = now.cost + 1;
                
                const int nextX = now.x + dx[i];
                if(0 <= nextX && nextX < w)
                {
                    //?¨?????????? ver
                    int nextX_sub = now.x + i - 1;

                    bool edge = nextX_sub < 0 || nextX_sub >= w;
                    nextX_sub = max(0, min(nextX_sub, w - 1));

                    if(map_ver[now.y][nextX_sub] == 0 && !edge)
                    {
                        if(min_cost[now.y][nextX] > nextCost)
                        {
                            min_cost[now.y][nextX] = nextCost;
                            path.push( Path{ Pos(nextX, now.y), nextCost } );
                        }
                    }
                }


                const int nextY = now.y + dy[i];
                if(0 <= nextY && nextY < h)
                {
                    //??????????????? hor
                    
                    int nextY_sub = now.y + i - 1;

                    bool edge = nextY_sub < 0 || nextY_sub >= h;
                    nextY_sub = max(0, min(nextY_sub, h - 1));

                    if(map_hor[nextY_sub][now.x] == 0 && !edge)
                    {
                        if(min_cost[nextY][now.x] > nextCost)
                        {
                            min_cost[nextY][now.x] = nextCost;
                            path.push( Path{ Pos(now.x, nextY), nextCost } );
                        }
                    }
                }

            }

        }
        /*
        for(int i = 0; i < h; i++)
        {
            for(int j = 0; j < w; j++)
            {
                cout << setw(3) << min(100, min_cost[i][j]) << " ";
            }
            cout << endl;
        }
        //*/
        cout << ((min_cost[h - 1][w - 1] == INF) ? 0 : min_cost[h - 1][w - 1]) << endl;
    }   

}