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 <string>
#include <algorithm>
#include <vector>
#include <utility>
#include <queue>
using namespace std;

#define rep(i,n) for(int i=0; i<n; i++)
const int INF = 1000000;

enum {
    DIR_UP,
    DIR_LEFT,
    DIR_RIGHT,
    DIR_DOWN,
};

int main(){
    int w, h;
    while( cin >> w >> h, w||h ) {
        bool wall[30][30][4];
        int maze[30][30];
        rep(y,h)  rep(x,w)  maze[x][y] = INF;
        rep(i, 2*h-1) {
            if( i%2 ) {
                // 横壁
                int y = i/2;
                rep(x, w) {
                    int k;
                    cin >> k;
                    wall[x][y][DIR_DOWN] = (k==0);
                    wall[x][y+1][DIR_UP] = (k==0);
                }
            } else {
                // 縦壁
                int y = i/2;
                rep(x, w-1) {
                    int k;
                    cin >> k;
                    wall[x][y][DIR_RIGHT] = (k==0);
                    wall[x+1][y][DIR_LEFT] = (k==0);
                }
            }
        }
        // 外周
        rep(y, h) {
            wall[0][y][DIR_LEFT] = false;
            wall[w-1][y][DIR_RIGHT] = false;
        }
        rep(x, w) {
            wall[x][0][DIR_UP] = false;
            wall[x][h-1][DIR_DOWN] = false;
        }

        queue< pair<int,int> > que;
        que.push( make_pair<int,int>(0, 0) );
        maze[0][0] = 1;

        while( !que.empty() ) {
            int x = que.front().first;
            int y = que.front().second;
            if( x==w-1 && y==h-1 ) {
                break;
            }
            que.pop();
            if( wall[x][y][DIR_UP] && maze[x][y-1]>maze[x][y]+1 ) {
                maze[x][y-1] = maze[x][y] + 1;
                que.push( make_pair<int, int>(x, y-1) );
            }
            if( wall[x][y][DIR_LEFT] && maze[x-1][y]>maze[x][y]+1 ) {
                maze[x-1][y] = maze[x][y] + 1;
                que.push( make_pair<int, int>(x-1, y) );
            }
            if( wall[x][y][DIR_RIGHT] && maze[x+1][y]>maze[x][y]+1 ) {
                maze[x+1][y] = maze[x][y] + 1;
                que.push( make_pair<int, int>(x+1, y) );
            }
            if( wall[x][y][DIR_DOWN] && maze[x][y+1]>maze[x][y]+1 ) {
                maze[x][y+1] = maze[x][y] + 1;
                que.push( make_pair<int, int>(x, y+1) );
            }
        }
        if( maze[w-1][h-1] == INF ) maze[w-1][h-1] = 0;
        cout << maze[w-1][h-1] << endl;

    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#define INF 18446744073709551615
using namespace std;

int h, w;
unsigned long long int mini;
int vecX[30][30], vecY[30][30];

void solMaze(int x, int y, unsigned long long int sum, vector< vector<bool> > check) 
{
	if (x >= w || y >= h || x < 0 || y < 0 || check[y][x] || sum >= mini || w - x + h - y + sum - 2 >= mini) {
		return;
	}

	check[y][x] = true;

	if (y == h - 1 && x == w - 1) {
		if (sum < mini) {
			mini = sum;
		}
		return;
	}

	if (vecX[y][x] == 0) {
		solMaze(x + 1, y, sum + 1, check);
	} 
	if (x >= 1) {
		if (vecX[y][x - 1] == 0) {
			solMaze(x - 1, y, sum + 1, check);
		}
	}
	if (vecY[y][x] == 0) {
		solMaze(x, y + 1, sum + 1, check);
	}
	if (y >= 1) {
		if (vecY[y - 1][x] == 0) {
			solMaze(x, y - 1, sum + 1, check);
		}
	}

}

int main(void)
{
	vector< vector<bool> > check(30, vector<bool>(30));
	while (1) {
		mini = INF;
		for (int i = 0; i < 30; ++i) {
			for (int j = 0; j < 30; ++j) {
				vecX[i][j] = 0;
				vecY[i][j] = 0;
				check[i][j] = false;
			}
		}
		cin >> w >> h;
		if (w == 0) {
			break;
		}
		for (int i = 0; i < h; ++i) {
			for (int j = 0; j < w - 1; ++j) {
				cin >> vecX[i][j];
			}
			if (i != h - 1) {
				for (int j = 0; j < w; ++j) {
					cin >> vecY[i][j];
				}
			}
 		}

 		solMaze(0, 0, 1, check);

 		if (mini == INF) {
 			mini = 0;
 		}
 		cout << mini << endl;

	}

	return 0;
}