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>

#define FOR(i, a, b) for(long long int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000 //2000000000
#define LLINF 1000000000000000000 //9000000000000000000
#define PI 3.14159265358979

using namespace std;
typedef long long int ll;
typedef pair< long long int, long long  int> P;


int main(void) {
	
	while (1) {
		int h, w;
		int wall;
		bool flag = true;
		bool check = false;
		int dp[65][65] = {};
		int checked[65][65] = {};
		pair<int, int>now;
		queue < pair <int, int > > que;

		cin >> w >> h;
		FOR(i, 0, 2*h) {
			dp[i][0] = 1;
			dp[i][2*w] = 1;
		}
		FOR(i, 0, 2*w) {
			dp[0][i] = 1;
			dp[2*h][i] = 1;
		}

		if (w == 0) {
			break;
		}
		FOR(i, 1, 2 * h - 1) {
			if (flag) {
				FOR(j, 1, w - 1) {
					cin >> wall;
					if (wall == 1) {
						dp[i][j * 2] = 1;
					}
				}
				flag = false;
			}
			else {
				FOR(j, 1, w) {
					cin >> wall;
					if (wall == 1) {
						dp[i][j * 2 - 1] = 1;
					}
				}
				flag = true;
			}
		}
		checked[1][1] = 1;
		now.first = 1;
		now.second = 1;
		que.push(now);
		while (!que.empty()) {
			now = que.front();
			que.pop();
			if (now.second == 2 * w - 1 && now.first == 2 * h - 1) {
				cout << checked[now.first][now.second] << endl;
				check = true;
				break;
			}
			if (now.second + 2 <= 2 * w) {
				if (dp[now.first][now.second+1] == 0 && dp[now.first][now.second + 2] == 0&&checked[now.first][now.second+2]==0) {
					checked[now.first][now.second+2] = checked[now.first][now.second] + 1;
					que.push(make_pair(now.first,now.second+2));
				}
			}
			if (now.second - 2 >=0) {
				if (dp[now.first][now.second - 1] == 0 && dp[now.first][now.second - 2] == 0 && checked[now.first][now.second - 2] == 0) {
					checked[now.first][now.second - 2] = checked[now.first][now.second] + 1;
					que.push(make_pair(now.first, now.second-2));
				}
			}
			if (now.first + 2 <= 2 * h) {
				if (dp[now.first+1][now.second] == 0 && dp[now.first+2][now.second] == 0 && checked[now.first+2][now.second] == 0) {
					checked[now.first+2][now.second ] = checked[now.first][now.second] + 1;
					que.push(make_pair(now.first+2, now.second));
				}
			}
			if (now.first - 2 >= 0) {
				if (dp[now.first - 1][now.second] == 0 && dp[now.first - 2][now.second] == 0 && checked[now.first - 2][now.second] == 0) {
					checked[now.first - 2][now.second] = checked[now.first][now.second] + 1;
					que.push(make_pair(now.first - 2, now.second));
				}
			}
		}
		if (!check) {
			cout << 0 << endl;
		}
	}
	
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#define rep(i, n) for(int i = 0; i < (int)(n); ++i)
#define REP(i, n) for(int i = 1; i < (int)(n); ++i)
using namespace std;

int main() {
    int h, w;
    cin >> w >> h;
    if (h == 0 && w == 0) return 0;
    vector<vector<int>> tatenokabe(h, vector<int>(w - 1));
    vector<vector<int>> yokonokabe(h - 1, vector<int>(w));
    rep(i, h - 1) {
        rep(j, w - 1) cin >> tatenokabe[i][j];
        rep(j, w) cin >> yokonokabe[i][j];
    }
    rep(j, w - 1) cin >> tatenokabe[h - 1][j];
    
    vector<vector<int>> dist(h, vector<int>(w, 0));
    queue<int> q;
    dist[0][0] = 1;
    q.push(0);
    while (q.size()) {
        int x = q.front() % w;
        int y = q.front() / w;
        q.pop();
        if (w > x + 1) {
            if (tatenokabe[y][x] == 0 && dist[y][x + 1] == 0) {
                dist[y][x + 1] = dist[y][x] + 1;
                q.push(y * w + x + 1);
            }
        }
        if (h > y + 1) {
            if (yokonokabe[y][x] == 0 && dist[y + 1][x] == 0) {
                dist[y + 1][x] = dist[y][x] + 1;
                q.push((y + 1) * w + x);
            }
        }
        if (x > 0) {
            if (tatenokabe[y][x - 1] == 0 && dist[y][x - 1] == 0) {
                dist[y][x - 1] = dist[y][x] + 1;
                q.push(y * w + x - 1);
            }
        }
        if (y > 0) {
            if (yokonokabe[y - 1][x] == 0 && dist[y - 1][x] == 0) {
                dist[y - 1][x] = dist[y][x] + 1;
                q.push((y - 1) * w + x);
            }
        }
    }
    cout << dist[h - 1][w - 1] << endl;
    main();
}