Go: package main

import (
	"fmt"
	"math"
)

type Position struct {
	X int64
	Y int64
}

func (one Position) Distance(another Position) int64 {
	return int64(math.Abs(float64(one.X-another.X)) + math.Abs(float64(one.Y-another.Y)))
}

type PersonPosition struct {
	Takayuki Position
	Kazuyuki Position
}

func (one PersonPosition) Distance() int64 {
	return one.Takayuki.Distance(one.Kazuyuki)
}

type Status struct {
	Person PersonPosition
	Turn   int64
}

type PQStatus []*Status

func solve(h, w int64) {
	var tx, ty, kx, ky int64
	fmt.Scan(&tx, &ty, &kx, &ky)
	tx--
	ty--
	kx--
	ky--
	m := make([][]int64, h)
	for i := range m {
		m[i] = make([]int64, w)
		for j := int64(0); j < w; j++ {
			fmt.Scan(&m[i][j])
		}
	}
	start := &Status{Person: PersonPosition{Takayuki: Position{X: tx, Y: ty}, Kazuyuki: Position{X: kx, Y: ky}}, Turn: 0}
	pq := make(PQStatus, 0)
	pq = append(pq, start)
	dx := []int64{0, 1, 0, -1}
	dy := []int64{1, 0, -1, 0}
	memo := make(map[PersonPosition]int64, 0)
	ans := int64(102)
	for len(pq) > 0 {
		now := &Status{}
		*now = *pq[0]
		pq = pq[1:]
		if ans <= now.Turn {
			continue
		}
		if _, ok := memo[now.Person]; ok {
			continue
		}
		memo[now.Person] = now.Turn

		if now.Person.Distance() == 0 && ans > now.Turn {
			ans = now.Turn
		}

		for i := 0; i < 4; i++ {
			next := &Status{}
			*next = *now
			next.Person.Kazuyuki.X += dx[i]
			next.Person.Kazuyuki.Y += dy[i]
			if next.Person.Kazuyuki.X < 0 || next.Person.Kazuyuki.X >= w ||
				next.Person.Kazuyuki.Y < 0 || next.Person.Kazuyuki.Y >= h ||
				m[next.Person.Kazuyuki.Y][next.Person.Kazuyuki.X] == 1 {
				next.Person.Kazuyuki.X -= dx[i]
				next.Person.Kazuyuki.Y -= dy[i]
			}
			next.Person.Takayuki.X -= dx[i]
			next.Person.Takayuki.Y -= dy[i]
			if next.Person.Takayuki.X < 0 || next.Person.Takayuki.X >= w ||
				next.Person.Takayuki.Y < 0 || next.Person.Takayuki.Y >= h ||
				m[next.Person.Takayuki.Y][next.Person.Takayuki.X] == 1 {
				next.Person.Takayuki.X += dx[i]
				next.Person.Takayuki.Y += dy[i]
			}
			next.Turn++
			if next.Turn <= 100 {
				pq = append(pq, next)
			}
		}
	}
	if ans == 102 {
		fmt.Println("NA")
	} else {
		fmt.Println(ans)
	}
}

func main() {
	var h, w int64
	for {
		fmt.Scan(&h, &w)
		if h == 0 && w == 0 {
			break
		}
		solve(h, w)
	}
}

C++: #include <iostream>
#include <queue>
#include <cstring>
using namespace std;

int field[50][50];
bool visit[50][50][50][50];

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

int main()
{
	int w,h,ax,ay,bx,by;

	while(cin >> w >> h, w||h)
	{
		cin >> ax >> ay;
		cin >> bx >> by;

		for(int y=0; y<h; y++)
		for(int x=0; x<w; x++)
		{
			cin >> field[y][x];
		}
		memset(visit,0,sizeof(visit));

		int cnt=0;
		bool flag=false;
		queue<int> q;
		q.push(ax-1);
		q.push(ay-1);
		q.push(bx-1);
		q.push(by-1);
		visit[ax][ay][bx][by] = 1;

		while(!q.empty())
		{
			int len=q.size()/4;
			for(int l=0; l<len; l++)
			{
				ax=q.front(); q.pop();
				ay=q.front(); q.pop();
				bx=q.front(); q.pop();
				by=q.front(); q.pop();

				if(ax==bx && ay==by)
				{
					flag=true;
					break;
				}

				for(int d=0; d<4; d++)
				{
					int px = ax+dx[d];
					int py = ay+dy[d];
					int qx = bx-dx[d];
					int qy = by-dy[d];

					if(px<0 || w<=px || py<0 || h<=py) { px=ax; py=ay; }
					if(qx<0 || w<=qx || qy<0 || h<=qy) { qx=bx; qy=by; }
					if(field[py][px]) { px=ax; py=ay; }
					if(field[qy][qx]) { qx=bx; qy=by; }

					if(!visit[px][py][qx][qy])
					{
						q.push(px);
						q.push(py);
						q.push(qx);
						q.push(qy);
						visit[ax][ay][bx][by] = 1;
					}
				}
			}

			if(flag) break;
			if(++cnt>=100) break;
		}

		if(flag)
		{
			cout << cnt << endl;
		}
		else
		{
			cout << "NA" << endl;
		}
	}

}

C++: #include <iostream>
#include <utility>
#include <queue>
#include <map>
using namespace std;

typedef pair<int,int> __P;
typedef pair<__P,__P> _P;
typedef pair<_P,int> P;

#define C(A,B) (0<=(A)&&(A)<(B))

int main() {
	queue<P> que;
	map<P,bool> mp;
	int X,Y;
	int tx,ty;
	int kx,ky;
	int count;
	int d[50][50];
	int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};
	while(true) {
		cin>>X>>Y;
		if(X==0&&Y==0) break;
		cin>>tx>>ty;
		cin>>kx>>ky;
		tx--;ty--;kx--;ky--;
		for(int i=0;i<Y;i++) {
			for(int j=0;j<X;j++) {
				cin>>d[i][j];
			}
		}
		que.push(P(_P(__P(tx,ty),__P(kx,ky)),0));
		count=-1;
		while(que.size()) {
			P& p=que.front();
			tx=p.first.first.first;
			ty=p.first.first.second;
			kx=p.first.second.first;
			ky=p.first.second.second;
			if(p.second>=100) {
				break;
			}
			if(mp[p]==true) {
				break;
			}
			if(tx==kx&&ty==ky) {
				count=p.second;
				break;
			}
			mp[p]=true;
			for(int i=0;i<4;i++) {
				int ntx=tx,nty=ty,nkx=kx,nky=ky;
				if(C(ntx+dx[i],X)&&C(nty+dy[i],Y)&&!d[ntx+dx[i]][nty+dy[i]]) {
					ntx+=dx[i],nty+=dy[i];
				}
				if(C(nkx-dx[i],X)&&C(nky-dy[i],Y)&&!d[nkx-dx[i]][nky-dy[i]]) {
					nkx-=dx[i],nky-=dy[i];
				}
				que.push(P(_P(__P(ntx,nty),__P(nkx,nky)),p.second+1));
			}
			
			que.pop();
		}
		if(count!=-1) {
			cout<<count<<endl;
		}else {
			cout<<"NA"<<endl;
		}
	}
	return 0;
}

C++: // AOJ 0223
#include <iostream>
#include <queue>
#include <map>
#include <algorithm>

using namespace std;

#define x first
#define y second
#define mp make_pair

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

typedef pair <int, int> Point;
typedef pair <Point, Point> kotori;
bool otonoki[64][64];
int x, y;

ostream &operator<<(ostream &os, const Point &a) { os << "(" << a.x << ", " << a.y << ")"; return os; }

bool is_region(Point p)
{
	return (0 <= p.x && p.x < x && 0 <= p.y && p.y < y);
}

int main()
{
	while (cin >> x >> y, x || y){
		Point s1, s2;
		cin >> s1.x >> s1.y;
		cin >> s2.x >> s2.y;
		s1.x--; s1.y--;
		s2.x--; s2.y--;
		for (int i = 0; i < y; i++){
			for (int j = 0; j < x; j++){
				cin >> otonoki[i][j];
			}
		}

		// cout << "in" << endl;

		map <kotori, bool> vst;
		queue <pair <kotori, int> > q;
		q.push(mp(mp(s1, s2), 0));
		bool f = false;
		while (!q.empty()){
			Point honoka = q.front().first.first, umi = q.front().first.second;
			int steps = q.front().second;
			q.pop();
			if (honoka == umi){
				cout << steps << endl;
				f = true;
				break;
			}
			if (vst[mp(honoka, umi)]) continue;
			vst[mp(honoka, umi)] = true;
			// cout << steps << " : " << honoka << " " << umi << endl;
			for (int i = 0; i < 4; i++){
				Point nh = honoka, nu = umi;
				nh.x += dx[i], nh.y += dy[i];
				nu.x -= dx[i], nu.y -= dy[i];

				// cout << nh << " " << nu << endl;
				if (!is_region(nh) && !is_region(nu)) continue;
				if (vst[mp(nh, nu)]) continue;
				
				if (!is_region(nh)) nh.x -= dx[i], nh.y -= dy[i];
				if (!is_region(nu)) nu.x += dx[i], nu.y += dy[i];
				if (otonoki[nh.y][nh.x]) continue;
				if (otonoki[nu.y][nu.x]) continue;
				q.push(mp(mp(nh, nu), steps + 1));
			}
		}
		if (!f) cout << "NA" << endl;
	}

	return 0;
}