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;

const double pi  = 2 * acos(0.0);
const double eps = 1e-8;

#define REP(i,a,b) for(int i=(a); i<(b);++i)
#define rep(i,n) REP(i,0,n)
#define INF (1<<29)

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

typedef int Cost;
struct Edge {
  int src, dst; Cost cost;
  Edge(int s, int d, Cost c) : src(s), dst(d), cost(c) {}
};
typedef vector<Edge>  Edges;
typedef vector<Edges> Graph;
typedef vector<Cost>  Array;
typedef vector<Array> Matrix;
typedef pair<int, int> P;

int dx[8] = {0, 1, 0, -1, 1, -1, 1, -1};
int dy[8] = {1, 0, -1, 0, 1, -1, -1, 1};

int w, h;
bool yoko[30][30];
bool tate[30][30];
int d[30][30];

int bfs() {
  queue<P> que;
  rep(x, w) rep(y, h) {
    d[x][y] = INF;
  }
  que.push(P(0, 0));
  d[0][0] = 0;

  while (que.size()) {
    P p = que.front(); que.pop();
    if (p.first == w - 1 && p.second == h - 1) break;

    if (0 <= p.first
        && p.first <= w - 2
        && !yoko[p.first][p.second]
        && d[p.first+1][p.second] == INF) {
      que.push(P(p.first+1, p.second));
      d[p.first+1][p.second] = d[p.first][p.second] + 1;
      // printf("(%d, %d){d=%d} to (%d, %d){d=%d}\n"
      //     ,p.first
      //     ,p.second
      //     ,d[p.first][p.second]
      //     ,p.first+1
      //     ,p.second
      //     ,d[p.first][p.second]);
    }

    if (0 <= p.second-1
        && p.second-1 <= h-2
        && !tate[p.first][p.second-1]
        && d[p.first][p.second-1] == INF) {
      que.push(P(p.first, p.second-1));
      d[p.first][p.second-1] = d[p.first][p.second] + 1;
      // printf("(%d, %d){d=%d} to (%d, %d){d=%d}\n"
      //     ,p.first
      //     ,p.second
      //     ,d[p.first][p.second]
      //     ,p.first
      //     ,p.second-1
      //     ,d[p.first][p.second-1]);
    }

    if (0 <= p.first-1
        && p.first-1 <= w-2
        && !yoko[p.first-1][p.second]
        && d[p.first-1][p.second] == INF) {
      que.push(P(p.first-1, p.second));
      d[p.first-1][p.second] = d[p.first][p.second] + 1;
      // printf("(%d, %d){d=%d} to (%d, %d){d=%d}\n"
      //     ,p.first
      //     ,p.second
      //     ,d[p.first][p.second]
      //     ,p.first-1
      //     ,p.second
      //     ,d[p.first-1][p.second]);
    }

    if (0 <= p.second
        && p.second <= h - 2
        && !tate[p.first][p.second]
        && d[p.first][p.second+1] == INF) {
      que.push(P(p.first, p.second+1));
      d[p.first][p.second+1] = d[p.first][p.second] + 1;
      // printf("(%d, %d){d=%d} to (%d, %d){d=%d}\n"
      //     ,p.first
      //     ,p.second
      //     ,d[p.first][p.second]
      //     ,p.first
      //     ,p.second+1
      //     ,d[p.first][p.second+1]);
    }
  }

  return d[w-1][h-1];
}

int main(void) {
  ios_base::sync_with_stdio(false); cin.tie(0);
  while (cin >> w >> h, w || h) {
    rep(i, 2 * h - 1) {
      if (i % 2 == 0) {
        rep(j, w - 1) cin >> yoko[j][i/2];
      } else {
        rep(j, w) cin >> tate[j][i/2];
      }
    }

    // printf("w: %d, h: %d\n", w, h);
    // cout << "Yoko" << endl;
    // rep(x, w - 1) rep(y, h) {
    //   if (yoko[x][y]) printf("(x, y) = (%d, %d) = true\n", x, y);
    //   else printf("(x, y) = (%d, %d) = false\n", x, y);
    // }
    //
    // cout << "Tate" << endl;
    // rep(x, w) rep(y, h - 1) {
    //   if (tate[x][y]) printf("(x, y) = (%d, %d) = true\n", x, y);
    //   else printf("(x, y) = (%d, %d) = false\n", x, y);
    // }

    int d = bfs();
    if (d == INF) cout << 0 << endl;
    else cout << d + 1 << endl;
  }
  return 0; 
}