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++: // AOJ 1166

#include <iostream>
#include <algorithm>
#include <queue>

using namespace std;

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

typedef pair <int, int> P;

int main(void)
{
	int w, h;
	while (cin >> w >> h, w && h){
		int wall[128][128], floor[128][128];

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


		int field[128][128];
		for (int i = 0; i < 128; i++){
			fill(field[i], field[i] + 128, 0);
		}
		field[0][0] = 1;
		queue <P> q;
		q.push(P(0, 0));
		// first = y, i, h ; second = x, j, w
		while (q.size()){
			P p = q.front();
			q.pop();
			int x = p.second, y = p.first;
			// cout << y << " " << x << endl;
			if (x == (w - 1) && y == (h - 1)){
				break;
			}
			for (int i = 0; i < 4; i++){
				int nx = x + dx[i], ny = y + dy[i];
				if (nx < 0 || ny < 0 || w-1 < nx || h-1 < ny) continue;
				// もうきてるよ
				if (field[ny][nx]) continue;

				if (i == 0 && floor[y][x]) continue;
/*
					// 下に行く
					// i,j -> floor[i][j]
					// 1 NG 0 OK
					if (floor[y][x]) continue;
					q.push(P(ny, nx));
					field[ny][nx] = field[y][x] + 1;
				}
*/
				if (i == 1 && floor[ny][nx]) continue;
/*
					// 上にいく
					// i,j -> floor[i-1][j]
					if (floor[ny-1][nx]) continue;
					q.push(P(ny, nx));
					field[ny][nx] = field[y][x] + 1;
				}
*/	
				if (i == 2 && wall[y][x]) continue;
/*
					// みぎ
					// i,j -> wall[i][j]
					if (wall[y][x]) continue;
					q.push(P(ny, nx));
					field[ny][nx] = field[y][x] + 1;
				}
*/				
				if (i == 3 && floor[ny][nx]) continue;
/*
					// ひだり
					// i,j -> wall[i][j-1]
					if (nx == 0 || floor[ny][nx-1]) continue;
					q.push(P(ny, nx));
					field[ny][nx] = field[y][x] + 1;
				}
*/
				field[ny][nx] = field[y][x] + 1;
				q.push(P(ny, nx));
			}
		}

		cout << field[h-1][w-1] << endl;
	}

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

const int dy[4] = {0, -1, 0, 1};
const int dx[4] = {1, 0, -1, 0};

int main() {
    int w, h;
    while (cin >> w >> h, w) {
        vector<vector<int>> wall(h, vector<int>(w, 0));
        for (int i = 0; i < 2 * h - 1; ++i) {
            if (i % 2 == 0) {
                for (int j = 0; j < w - 1; ++j) {
                    int c;
                    cin >> c;
                    if (c) continue;
                    wall[i / 2][j] |= 1 << 0;
                    wall[i / 2][j + 1] |= 1 << 2;
                }
            } else {
                for (int j = 0; j < w; ++j) {
                    int c;
                    cin >> c;
                    if (c) continue;
                    wall[i / 2][j] |= 1 << 3;
                    wall[i / 2 + 1][j] |= 1 << 1;
                }
            }
        }
        vector<vector<int>> dis(h, vector<int>(w, 0));
        queue<pair<int, int>> que;
        dis[0][0] = 1;
        que.emplace(0, 0);
        while (!que.empty()) {
            int y, x;
            tie(y, x) = que.front(); que.pop();
            for (int i = 0; i < 4; ++i) {
                int ny = y + dy[i];
                int nx = x + dx[i];
                if (ny >= 0 && ny < h && nx >= 0 && nx < w && (wall[y][x] >> i & 1) && !dis[ny][nx]) {
                    dis[ny][nx] = dis[y][x] + 1;
                    que.emplace(ny, nx);
                }
            }
        }
        cout << dis[h - 1][w - 1] << endl;
    }
}