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 <iostream>

using namespace std;

const int YOKO = 0;
const int TATE = 1;
const int BLOCK_WIDTH = 4;
const int BLOCK_HEIGHT = 2;

int map[101][101];
int pmap[101][101];
int w, h;
int xs, ys, xg, yg;
bool answer = false;

void init() {
  answer = false;
  for (int i = 0; i < 101; i++) {
    for (int j = 0; j < 101; j++) {
      map[i][j] = 0;
      pmap[i][j] = 0;
    }
  }
}

void set_block(int c, int d, int x, int y) {
  int height, width;
  if (d == YOKO) {
    height = BLOCK_HEIGHT;
    width = BLOCK_WIDTH;
  } else {
    height = BLOCK_WIDTH;
    width = BLOCK_HEIGHT;
  }
  for (int i = 0; i < height; i++) {
    for (int j = 0; j < width; j++) {
      map[y + i][x + j] = c;
    }
  }
}

void find(int c, int x, int y) {
  if (c == map[y][x]) {
    pmap[y][x] = 1;
  }
  if (pmap[yg][xg]) {
    answer = true;
    return;
  }
  if (x - 1 > 0 && c == map[y][x - 1] && !pmap[y][x - 1]) {
    find(c, x - 1, y);
  }
  if (x + 1 < 101 && c == map[y][x + 1] && !pmap[y][x + 1]) {
    find(c, x + 1, y);
  }
  if (y - 1 > 0 && c == map[y - 1][x] && !pmap[y - 1][x]) {
    find(c, x, y - 1);
  }
  if (y + 1 < 101 && c == map[y + 1][x] && !pmap[y + 1][x]) {
    find(c, x, y + 1);
  }
}

int main() {
  int n, c, d, x, y;
  while(cin >> w >> h, w) {
    cin >> xs >> ys;
    cin >> xg >> yg;
    cin >> n;
    init();
    for (int i = 0; i < n; i++) {
      cin >> c >> d >> x >> y;
      set_block(c, d, x, y);
    }
    find(map[ys][xs], xs, ys);
    cout << ((answer) ? "OK" : "NG") << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <unordered_map>
#include <ctime>
#include <list>
#include <numeric>
#include <utility>
#include <ctime>
#define INF 100000000
#define LINF 9000000000000000000
#define mod 1000000007
 
#define rep(i,n) for(int i=0;i<int(n);i++)
#define REP(i,a,b) for(int i=(a);i<int(b);i++)
#define all(x) (x).begin(),x.end()
#define pb push_back
#define mp make_pair
#define MOD(x) (x%(mod))
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef pair<int,int> pi;
 
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
bool debug=false;

/*---------------------------------------------------*/

int maze[305][305];
int w,h,xs,ys,xg,yg;

void init(){
  rep(i,305){
    rep(j,305){
      maze[i][j]=-1;
    }
  }
}

bool bfs(int c){
  queue<int>que;
  que.push(xs);
  que.push(ys);
  while(que.size()){
    int x=que.front();que.pop();
    int y=que.front();que.pop();
    if(x==xg&&y==yg)return true;
    for(int i=0;i<4;i++){
      if(0<=x+dx[i]&&x+dx[i]<w&&0<=y+dy[i]&&y+dy[i]<h&&maze[y+dy[i]][x+dx[i]]==c){
	que.push(x+dx[i]);
	que.push(y+dy[i]);
	maze[y+dy[i]][x+dx[i]]=-1;
      }
    }
  }
  return false;
}

int main(){
  int n,c,d,x,y;
  while(cin>>w>>h){
    if(w==0&&h==0)break;
    init();
    cin>>xs>>ys;
    cin>>xg>>yg;
    cin>>n;
    rep(i,n){
      cin>>c>>d>>x>>y;
      if(d==0){
	rep(j,2){
	  rep(k,4){
	    maze[y+j][x+k]=c;
	  }
	}
      }else if(d==1){
	rep(j,4){
	  rep(k,2){
	    maze[y+j][x+k]=c;
	  }
	}
      }
    }
    if(bfs(c))cout<<"OK"<<endl;
    else cout<<"NG"<<endl;
  }
  return 0;
}

C++: /* 0207 */
#include <iostream>
using namespace std;
int n,w,h;
int M[101][101];
int sx,sy,ex,ey;

int walk(int x,int y,int color){
	if(x<1||w<x||y<1||h<y)return 0;
	if(color!=M[x][y]||color==0)return 0;
	M[x][y]=9;
	if(x==ex&&y==ey)return 1;
	if(walk(x+1,y,color)|| walk(x-1,y,color)|| walk(x,y+1,color)|| walk(x,y-1,color))return 1;
	return 0;
}
int main(void){
	while(cin>>w>>h,w||h){
		cin>>sx>>sy>>ex>>ey;
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				M[i][j]=0;
			}
		}
		int k;
		cin>>k;
		for(int i=0;i<k;i++){
			int w,x,y,z;
			cin>>w>>x>>y>>z;
			if(x){
				for(int Y=z;Y<z+4;Y++){
					for(int X=y;X<y+2;X++){
						M[Y][X]=w;
					}
				}
			}else{
				for(int Y=z;Y<z+2;Y++){
					for(int X=y;X<y+4;X++){
						M[Y][X]=w;
					}
				}
			}
		}
		// for(int i=1;i<=h;i++){
		// 	for(int j=1;j<=w;j++){
		// 		cout<<M[i][j]<<" ";
		// 	}
		// 	cout<<endl;
		// }
		if((sy==ey&&sx==ex)||walk(sx,sy,M[sx][sy]))cout<<"OK"<<endl;
		else cout<<"NG"<<endl;
		// if(M[c][d]==9)cout<<"OK"<<endl;
		// else cout<<"NG"<<endl;
	}
	return 0;
}

C++: //メモリ数確認したか?
#include<iostream>
#include<cstdio>
#include<string>
#include<vector>
#include<algorithm>
#include<cstdlib>
using namespace std;
typedef long long int ll;
bool s[100][100];
int w,h,xs,ys,xg,yg,n;
int boad[100][100];
int c,d,x,y;
int X[4]={-1,0,0,1};
int Y[4]={0,-1,1,0};
void f(int x,int y){
	s[x][y]=true;
	for(int i=0;i<4;i++){
		if(x+X[i]>=0&&x+X[i]<w&&y+Y[i]>=0&&y+Y[i]<h){
			if(!s[x+X[i]][y+Y[i]]){
				if(boad[x][y]==boad[x+X[i]][y+Y[i]]){
					f(x+X[i],y+Y[i]);
				}
			}
		}
	}
}
int main()
{
	while(true){
	for(int i=0;i<100;i++){
		for(int j=0;j<100;j++){
			boad[i][j]=0;
			s[i][j]=false;
		}
	}
	scanf("%d%d",&w,&h);
	if(w==0&&h==0)return 0;
	scanf("%d%d%d%d%d",&xs,&ys,&xg,&yg,&n);
	for(int i=0;i<n;i++){
		scanf("%d%d%d%d",&c,&d,&x,&y);
		if(d==1){
			for(int j=x-1;j<x+2-1;j++){
				for(int k=y-1;k<y+4-1;k++){
					boad[k][j]=c;
				}
			}
		}

		else{
			for(int j=x-1;j<x+4-1;j++){
				for(int k=y-1;k<y+2-1;k++){
					boad[k][j]=c;
				}
			}
		}
	}
	
	if(boad[xs-1][ys-1]==0||boad[xg-1][yg-1]==0){
		printf("NG\n");
		goto a;
	}
	f(xs-1,ys-1);
	
	if(s[xg-1][yg-1]){
		printf("OK\n");
	}
	else printf("NG\n");
a:;
	}
    return 0;
}
//メモリ数確認したか?