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 int MAXV = 101;
int visited[MAXV][MAXV], dist[MAXV][MAXV];
pair<int, int> parent[MAXV][MAXV];

const int offset[4][2] = {
    { -1, 0 }, { 0, -1 }, { 1, 0 }, { 0, 1 }
};



int wall1[MAXV][MAXV][MAXV];
int wall2[MAXV][MAXV][MAXV];
int H, W;


void bfs(int i, int j){
    memset(parent, -1, sizeof(parent));
    memset(dist, 0, sizeof(dist));
    memset(visited, 0, sizeof(visited));
    
    
    queue<pair<int, int>> q;
    q.push(make_pair(i, j));
    visited[i][j] = 1, dist[i][j] = 0;
    
    while (!q.empty()) {
        pair<int, int> u = q.front();
        q.pop();
        
        for (int k = 0; k < 4; k++) {
            int ii = u.first + offset[k][0], jj = u.second + offset[k][1];
            if (ii < 0 || jj < 0 || ii >= H || jj >= W) {
                continue;
            }
            if (!visited[ii][jj]) {
                if (u.first == ii && !wall1[u.first][u.second][jj]) {
                    visited[ii][jj] = 1, parent[ii][jj] = u;
                    dist[ii][jj] = dist[u.first][u.second] + 1;
                    q.push(make_pair(ii, jj));
                } else if (u.second == jj && !wall2[u.first][ii][u.second]){
                    visited[ii][jj] = 1, parent[ii][jj] = u;
                    dist[ii][jj] = dist[u.first][u.second] + 1;
                    q.push(make_pair(ii, jj));
                }
            }
        }
    }
}



int main(int argc, char *argv[])
{
    
 
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    memset(wall1, -1, sizeof(wall1));
    memset(wall2, -1, sizeof(wall2));
    
    while (cin >> W >> H, W > 0 && H > 0) {
        for (int i = 0; i < H; i++) {
            for (int j = 1; j < W; j++) {
                cin >> wall1[i][j-1][j];
                wall1[i][j][j-1] = wall1[i][j-1][j];
            }
            if (i == H - 1) {
                continue;
            }
            for (int j = 0; j < W; j++) {
                cin >> wall2[i][i+1][j];
                wall2[i+1][i][j] = wall2[i][i+1][j];
            }
        }
        bfs(0, 0);
        if (!dist[H-1][W-1]) {
            cout << dist[H-1][W-1] << endl;
        } else {
            cout << dist[H-1][W-1]+1 << endl;
        }
    }
    
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <functional>

using namespace std;

typedef pair<int, int> P;
typedef pair<int, P> Q;

int main() {
	int w, h;
	while (cin >> w >> h) {
		if (w == 0 && h == 0) {
			break;
		}
		vector< vector<int> > hyou(2*h+1, vector<int>(2*w+1, 0));
		for (int i = 0; i < 2*w+1; i++) {
			hyou[0][i] = hyou[2*h][i] = 1;
		}
		for (int i = 0; i < 2*h+1; i++) {
			hyou[i][0] = hyou[i][2*w] = 1;
		}
		for (int i = 1; i < 2*h; i++) {
			if (i % 2 == 1) {
				for (int j = 2; j < 2*w; j+=2) {
					cin >> hyou[i][j];
				}
			} else {
				for (int j = 1; j < 2*w+1; j+=2) {
					cin >> hyou[i][j];
				}
			}
		}
		priority_queue< Q, vector<Q>, greater<Q> > pq;
		pq.push(Q(1, P(1, 1)));
		int dx[4] = {1, 0, -1, 0};
		int dy[4] = {0, 1, 0, -1};
		bool hantei = false;
		while (!pq.empty()) {
			Q q = pq.top();
			int x = (q.second).first;
			int y = (q.second).second;
			int k = q.first;
			k++;
			pq.pop();
			for (int i = 0; i < 4; i++) {
				if (hyou[x+dx[i]][y+dy[i]] == 0 && hyou[x+dx[i]*2][y+dy[i]*2] == 0) {
					if (x+dx[i]*2 == 2*h-1 && y+dy[i]*2 == 2*w-1) {
						hantei = true;
						cout << k << endl;
						break;
					}
					hyou[x+dx[i]*2][y+dy[i]*2] = 1;
					pq.push(Q(k, P(x+dx[i]*2, y+dy[i]*2)));
				}
			}
			if (hantei) {
				break;
			}
		}
		if (!hantei) {
			cout << 0 << endl;
		}
	}
	return 0;
}