Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

var (
	dx = []int{0, -1, 0, 1}
	dy = []int{1, 0, -1, 0}
)

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		w, _ := strconv.Atoi(buf[0])
		h, _ := strconv.Atoi(buf[1])
		if w == 0 && h == 0 {
			break
		}
		scanner.Scan()
		buf_ := strings.Split(scanner.Text(), " ")
		xs, _ := strconv.Atoi(buf_[0])
		ys, _ := strconv.Atoi(buf_[1])
		scanner.Scan()
		buf__ := strings.Split(scanner.Text(), " ")
		xg, _ := strconv.Atoi(buf__[0])
		yg, _ := strconv.Atoi(buf__[1])
		xs--
		ys--
		xg--
		yg--
		scanner.Scan()
		n, _ := strconv.Atoi(scanner.Text())
		field := make([][]int, 100)
		for i := range  field {
			field[i] = make([]int, 100)
		}
		visited := make([][]bool, 100)
		for i := range visited {
			visited[i] = make([]bool, 100)
		}
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf___ := strings.Split(scanner.Text(), " ")
			c, _ := strconv.Atoi(buf___[0])
			d, _ := strconv.Atoi(buf___[1])
			x, _ := strconv.Atoi(buf___[2])
			y, _ := strconv.Atoi(buf___[3])
			x--
			y--
			switch d {
			case 0:
				for j := 0; j < 4; j++ {
					for k := 0; k < 2; k++ {
						field[x+j][y+k] = c
					}
				}
			case 1:
				for j := 0; j < 2; j++ {
					for k := 0; k < 4; k++ {
						field[x+j][y+k] = c
					}
				}
			}
		}
		if field[xs][ys] != field[xg][yg] || // スタートとゴールの色が等しくないと"NG"
			field[xs][ys] == 0 { // スタートの色が無職
			fmt.Println("NG")
			continue
		}
		Q := make([]Entry, 0)
		visited[xs][ys] = true
		Q = append(Q, Entry{xs, ys})
		for len(Q) > 0 {
			row := Q[0].x
			col := Q[0].y
			Q = Q[1:]
			for i := 0; i < 4; i++ {
				if 0 <= row+dx[i] && row+dx[i] < w &&
					0 <= col+dy[i] && col+dy[i] < h && // 移動可能な範囲内かどうか
					!visited[row + dx[i]][col + dy[i]] && // 訪問済みか
					field[row+dx[i]][col+dy[i]]==field[row][col] { // 色が同じかどうか
						visited[row+dx[i]][col+dy[i]] = true
						Q = append(Q, Entry{row+dx[i],col+dy[i]})
				}
			}
		}
		if visited[xg][yg] {
			fmt.Println("OK")
		} else {
			fmt.Println("NG")
		}
	}
}

type Entry struct {
	x, y int
}

C++: #include<map>
#include<queue>
#include<cstdio>
#include<cstring>
#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
#define SIZE 110
using namespace std;

typedef pair<int,int> P;

void make_mass(void);   //マス作成用関数
void solve(void);       //処理

int n;             //ブロックの個数
int w,h;           //ボードの幅、高さ
int goal=0;        //迷路になっているか
int scolor;        //スタート位置の色
int sx,sy,gx,gy;   //スタートの座標、ゴールの座標
int mass[SIZE][SIZE];
int data[SIZE][SIZE];
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
int c[SIZE],d[SIZE],x[SIZE],y[SIZE];       //ブロックの色、向き、左上の座標


int main(){

  int i,j;             //カウンタ変数

  while(1){

    /*情報の入力*/
    cin>>w>>h;

    if(w==h && w==0){break;}
    
    cin>>sx>>sy;
    cin>>gx>>gy;  
    cin>>n;
    
    for(i=0;i<n;i++){
      cin>>c[i]>>d[i]>>x[i]>>y[i];
      
    }
    
    make_mass();

    solve();
     
    if(goal==1){
      cout<<"OK"<<endl;
      goal=0;
    } else if(goal==0){
      cout<<"NG"<<endl;
      }
  }
  
  return 0;
}
void make_mass(void){
  
  int i,j;

  memset(mass,0,sizeof(mass));

  /*マスの作成*/
  for(i=0;i<n;i++){
    if(d[i]==0){       //横向きなら
      for(j=0;j<4;j++){
	mass[y[i]][x[i]+j]=c[i];
	mass[y[i]+1][x[i]+j]=c[i];
      }
    }
    if(d[i]==1){              //縦向きなら
      for(j=0;j<4;j++){
	mass[y[i]+j][x[i]]=c[i];
	mass[y[i]+j][x[i]+1]=c[i];
      }
    }
  }
  
  scolor=mass[sy][sx];

  
  return;
}
void solve(void){
  
  int i,j;
  queue<P> que;
  memset(data,-1,sizeof(data));
  que.push(P(sx,sy));     //queにスタート位置の座標を格納
  data[sy][sx]==0;
  
  while(!que.empty()){    //queが空でない間
    P p=que.front();
    que.pop();
    
    if(p.first==gx && p.second==gy){
      goal=1;
      /* cout<<" (^q^)くおえうえーーーるえうおおおwwww"<<endl;*/
      break;
    }
    for(i=0;i<4;i++){
      int nx=p.first+dx[i];
      int ny=p.second+dy[i];
      if(nx>=0 && nx<w && ny>=0 && ny<h && mass[ny][nx]==scolor && data[ny][nx]==-1){
	que.push(P(nx,ny));
	data[ny][nx]=1;
      }
    }
  }
  return;
}
/*
花火は他人に向けちゃダメだよ。

( ・ω・)o─━・*:・:・(※)`Д´)アヂィ!

*/

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

typedef pair<int,int> P;

int main(){
  int w,h;
  int xs,ys,xg,yg;
  int n;
  int c,d,x,y;
  int grid[101][101];
  bool visit[101][101];

  for(;;){
    cin >> w >> h;
    if(!w && !h)break;

    for(int i=1;i<=h;i++)
      for(int j=1;j<=w;j++){
	grid[i][j] = 0;
	visit[i][j] = false;
      }
    cin >> xs >> ys >> xg >> yg;

    cin >> n;
    for(int i=0;i<n;i++){
      cin >> c >> d >> x >> y;
      if(d){
	for(int j=0;j<4;j++)
	  for(int k=0;k<2;k++)grid[y+j][x+k] = c;
      }else{
	for(int j=0;j<2;j++)
	  for(int k=0;k<4;k++)grid[y+j][x+k] = c;
      }
    }
    /*
    for(int i=1;i<=h;i++){
      for(int j=1;j<=w;j++)cout << grid[i][j];
      cout << endl;
    }
    */
    int color = grid[ys][xs];    
    queue<P> q;
    if(color){
      q.push(P(ys,xs));
      
      while(q.size()){
	P p = q.front();q.pop();
	y = p.first;
	x = p.second;
	if(yg == y && xg == x){
	  cout << "OK\n";
	  q.push(P(y,x));
	  break;
	}
	visit[y][x] = true;
	
	int dx[] = {0,1,0,-1},dy[] = {-1,0,1,0};
	for(int i=0;i<4;i++){
	  int sx = x+dx[i],sy = y+dy[i];
	
	  if(sx<0 || sy<0 || w<=sx || h<=sy)continue;
	  
	  if(visit[sy][sx] || grid[sy][sx]!=color)continue;
	  q.push(P(sy,sx));
	}
      }
    }
    if(q.empty())cout << "NG\n";
  }
}

C++: #include<cstdio>
#include<iostream>
#include<string>
#include<string.h>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<stdlib.h>
#include<queue>
#include<map>
#include<vector>
#include<list>
#include<stack>
#include<functional>
 
using namespace std;
 
#define all(c) (c).begin(), (c).end()
#define rep(i,n) for(int i=0;i<n;i++)

 
const int INF=100000000;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0-1};
 
typedef pair<int ,int > P;
 
char maze[105][105];
 
int sx,sy;
int gx,gy;
int w,h;
 
char sc;        //スタート地点のカラー
 
//stdin
//stdout
 
void dfs(int x,int y)
{
    maze[y][x]='9';
 
    rep(i,4)
    {
/*        for(int j=-1;j<=1;j++)
        {*/
            int nx=x+dx[i];
            int ny=y+dy[i];
 
            if(0<=nx && nx<=w && 0<=ny && ny<=h &&maze[ny][nx]==sc)
            {
                dfs(nx,ny);
            }
 
/*        }*/
    }
    return ;
}
 
void solve()
{
 
    rep(i,101)
        rep(j,101)
        maze[i][j]='0';
 
    int n;
    char c;
    int d;
    int x,y;
 
    cin>>sx>>sy;
    cin>>gx>>gy;
 
    cin>>n;
 
    rep(i,n)
    {
        cin>>c>>d>>x>>y;
 
        if(d==1)
        {
            rep(j,2)
            {
                rep(k,4)
                {
                    maze[y+k][x+j]=c;
 
                }
            }
        }
        else if (d==0)
        {
            rep(j,4)
            {
                rep(k,2)
                {
                    maze[y+k][x+j]=c;
 
                }
            }
        }
 
    }
//6 6
//1 1
//3 6
//2
//1 0 1 1
//1 1 3 3
//  rep(i,w+1)
//  {
//      rep(j,h+1)
//      {
//          cout<<maze[i][j];
//
//      }
//      cout<<endl;
//  }
//
//  cout<<maze[gx][gy]<<endl;
 
    if(maze[sy][sx]=='0')
    {
        cout<<"NG"<<endl;
        return;
    }
    else
    {
        sc=maze[sy][sx];
        dfs(sx,sy);
    }
     
    //rep(i,w+1)
    //{
    //  rep(j,h+1)
    //  {
    //      cout<<maze[i][j];
 
    //  }
    //  cout<<endl;
    //}
 
    if(maze[gy][gx]=='9')
    {
        cout<<"OK"<<endl;
        return;
    }
    else
    {
        cout<<"NG"<<endl;
        return;
    }
 
 
 
}
 
int main()
{
 
    while(cin>>w>>h)
    {
        if(w==0 && h==0)
        {
            return 0;
        }
        else
        {
            solve();
        }
    }
 
 
    return 0;
}