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 <cstdio>
#include <queue>
#include <algorithm>

#define N 30

using namespace std;

struct P
{
  int c;
  int x;
  int y;

  P (
    const int c = 1,
    const int x = 0,
    const int y = 0
    )
  {
    this->c = c;
    this->x = x;
    this->y = y;
  }
};
typedef struct P P;

int
main (
  )
{
  int i, j;

  for ( ; ; )
  {
    queue<P> lis;
    int v[ N ][ N ][ 4 ] = { };
    int w, h;

    scanf ( "%d%d", &w, &h );
    if ( !( w | h ) ) break ;

    for ( i = 0; i < h; ++i )
    {
      if ( i > 0 )
      for ( j = 0; j < w; ++j )
      {
        int G__21;

        scanf ( "%d", &G__21 );
        v[ i ][ j - 1 ][ 1 ] =
        v[ i ][ j ][ 3 ] = G__21;
      }

      for ( j = 0; j < w - 1; ++j )
      {
        int G__21;

        scanf ( "%d", &G__21 );
        v[ i ][ j ][ 0 ] =
        v[ i ][ j + 1 ][ 2 ] = G__21;
      }
    }

    lis.push ( P ( ) );
    for ( ; ; )
    {
      P p = lis.front ( );
      lis.pop ( );

      if ( p.x == w - 1 && p.y == h - 1 )
      {
        printf ( "%d\n", p.c );
        break ;
      }

      if ( p.x < w - 1
        && !v[ p.y ][ p.x ][ 0 ] )
      {
        v[ p.y ][ p.x ][ 0 ] = 1;
        lis.push ( P ( p.c + 1, p.x + 1, p.y ) );
      }
      if ( p.y < h - 1
        && !v[ p.y ][ p.x ][ 1 ] )
      {
        v[ p.y ][ p.x ][ 1 ] = 1;
        lis.push ( P ( p.c + 1, p.x, p.y + 1 ) );
      }
      if ( p.x > 0
        && !v[ p.y ][ p.x ][ 2 ] )
      {
        v[ p.y ][ p.x ][ 2 ] = 1;
        lis.push ( P ( p.c + 1, p.x - 1, p.y ) );
      }
      if ( p.y > 0
        && !v[ p.y ][ p.x ][ 3 ] )
      {
        v[ p.y ][ p.x ][ 3 ] = 1;
        lis.push ( P ( p.c + 1, p.x, p.y - 1 ) );
      }

      if ( lis.empty ( ) )
      {
        puts ( "0" );
        break ;
      }
    }
  }

  return ( 0 );
}

C++: #include <algorithm>
#include <iostream>
#include <string>
#include <cstring>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <iomanip>
#include <limits>
#include <map>
#include <queue>
#include <stack>
#include <vector>

#define FOR(i,k,n) for(int (i) = (k); (i) < (n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define all(v) begin(v), end(v)
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x,y) cerr << #x << ": " << x << ", " << #y << ": " << y << endl

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<i_i, int> p_i;
typedef vector<int> vi;
typedef vector< vector<int> > vvi;
template<class T> using vv=vector< vector<T> >;
typedef deque<int> di;
typedef deque< deque<int> > ddi;

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


int main() {
    int w,h;  
    while(cin >> w >> h, w) {
        int m[35][35][4] = {}; // right, left, up, down
        int g[35][35] = {};
        FOR(i,1,h*2){
            if(i % 2 == 1) {
                FOR(j,1, w) {
                    int tmp;
                    cin >> tmp;
                    if(tmp == 0) { 
                        m[(i+1)/2][j][0] = 1;
                        m[(i+1)/2][j+1][1] = 1;
                    }
                }
            } else {
                FOR(j,1,w+1) {
                    int tmp;
                    cin >> tmp;
                    if(tmp == 0) {
                        m[i/2][j][3] = 1;
                        m[(i/2)+1][j][2] = 1;
                    }
                }
            }
        }

/*
        rep(i,h+1) {
            rep(j,w+1) {
                cout << "\"";
                rep(k,4) {
                    cout << m[i][j][k] << " ";
                }
                cout << "\"";
            }
            cout << endl; 
        }
*/

        queue<i_i> Q;
        Q.push(make_pair(1,1));
        g[1][1] = 1;
        while(!Q.empty()) {
            i_i tmp = Q.front();
            Q.pop();
            if(tmp.first == h && tmp.second == w) {
                break;
            }
            rep(i,4) {
                if(m[tmp.first][tmp.second][i] == 1 && g[tmp.first+dy[i]][tmp.second+dx[i]] == 0) {
                    //debug2(tmp.first+dy[i],tmp.second+dx[i]);
                    Q.push(make_pair(tmp.first+dy[i],tmp.second+dx[i]));
                    g[tmp.first+dy[i]][tmp.second+dx[i]] = g[tmp.first][tmp.second] + 1; 
                }
            }
        }
        cout << g[h][w] << endl;
    }
    return 0;
}