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>
# include <stack>
# include <cstring>

typedef std::pair<int, int> P;

constexpr int INF = (int)1e7;
constexpr int MAX = 100;

int w, h;
int board[MAX][MAX];
P start, goal;
int n;
int d[MAX][MAX], dx[4] = { 1,-1,0,0 }, dy[4] = { 0,0,1,-1 };

bool dfs(P s, P g) {
	bool res = false;
	for (int i = 0; i < h; ++i)
		for (int j = 0; j < w; ++j)
			d[i][j] = INF;
	std::stack<P> stk;
	stk.push(s);
	d[s.second][s.first] = 0;
	while (!stk.empty()) {
		P p = stk.top(); stk.pop();
		if (p == g) {
			res = true;
			break;
		}

		for (int i = 0; i < 4; ++i) {
			int nx = p.first + dx[i];
			int ny = p.second + dy[i];
			if (0 <= nx&&nx < w &&
				0 <= ny&&ny < h&&
				d[ny][nx] == INF&&board[ny][nx] == board[p.second][p.first]) {
				d[ny][nx] = d[p.second][p.first] + 1;
				stk.push(P(nx, ny));
			}
		}
	}
	return res;
}

int main() {
	while (1) {
		std::cin >> w >> h;
		if (w + h == 0)
			break;
		std::memset(board, 0, sizeof(board));

		std::cin >> start.first >> start.second
			>> goal.first >> goal.second >> n;
		--start.first;
		--start.second;
		--goal.first;
		--goal.second;
		int c, d, x, y;
		for (int i = 0; i < n; ++i) {
			std::cin >> c >> d >> x >> y;
			for (int i = 0; i < 4; ++i) {
				for (int j = 0; j < 2; ++j) {
					int& a = (d) ? board[y - 1 + i][x - 1 + j] : board[y - 1 + j][x - 1 + i];
					a = c;
				}
			}
		}

		if (dfs(start, goal))
			std::cout << "OK" << std::endl;
		else
			std::cout << "NG" << std::endl;
	}
	return 0;
}

C++: //include----------------------------------------------------------------------------------------------------------------------
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<string>
#include<cctype>
#include<string>
#include<vector>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<bitset>
#include<map>
#include<algorithm>
#include<memory>


//using namespace--------------------------------------------------------------------------------------------------------------
using namespace std;

//define,const-----------------------------------------------------------------------------------------------------------------
#define rep(i, n) for(int i = 0; i < n; i++)
const int INF = 1 << 25;
#define MAX 1000

//global-----------------------------------------------------------------------------------------------------------------------
int board_range_w, board_range_h, start_x, start_y, goal_x, goal_y;
int color[MAX][MAX];
bool dp[MAX][MAX];

//function---------------------------------------------------------------------------------------------------------------------
bool solve(int x, int y){
	if ( x == goal_x && y == goal_y )
		return true;
	if ( color[x][y] == color[x + 1][y] && dp[x + 1][y] )
		if ( solve(x + 1, y) )
			return true;
	if ( color[x][y] == color[x][y + 1] && dp[x][y + 1] )
		if ( solve(x, y + 1) )
			return true;
	if ( color[x][y] == color[x][y - 1] && dp[x][y - 1] )
		if ( solve(x, y - 1) )
			return true;
	if ( color[x][y] == color[x - 1][y] && dp[x - 1][y] )
		if ( solve(x - 1, y) )
			return true;
	dp[x][y] = false;
	return false;
}

int main(){
	while ( scanf("%d %d", &board_range_w, &board_range_h) ) {
		if ( board_range_w == 0 && board_range_h == 0 )
			return 0;
		for ( int i = 0; i <= board_range_w + 1; i++ ){
			for ( int j = 0; j <= board_range_h + 1; j++ ){
				color[i][j] = 0;
				dp[i][j] = true;
			}
		}
		scanf("%d %d", &start_x, &start_y);
		scanf("%d %d", &goal_x, &goal_y);
		int block;
		scanf("%d", &block);
		for ( int i = 0; i < block; i++ ){
			int block_color, block_quarter, block_start_x, block_start_y;
			scanf("%d %d %d %d", &block_color, &block_quarter, &block_start_x, &block_start_y);
			color[block_start_x + 1][block_start_y + 1] = block_color;
			color[block_start_x][block_start_y + 1] = block_color;
			color[block_start_x + 1][block_start_y] = block_color;
			color[block_start_x][block_start_y] = block_color;
			if ( !block_quarter ){
				color[block_start_x + 2][block_start_y + 1] = block_color;
				color[block_start_x + 2][block_start_y] = block_color;
				color[block_start_x + 3][block_start_y + 1] = block_color;
				color[block_start_x + 3][block_start_y] = block_color;
			}										
			else{
				color[block_start_x + 1][block_start_y + 3] = block_color;
				color[block_start_x][block_start_y + 3] = block_color;
				color[block_start_x + 1][block_start_y + 2] = block_color;
				color[block_start_x][block_start_y + 2] = block_color;
			}
		}
		if ( start_x > goal_x && start_y > goal_y ){
			swap(start_x, goal_x);
			swap(start_y, goal_y);
		}
		if ( solve(start_x, start_y) ) 
			printf("OK\n");
		else
			printf("NG\n");
	}
	return 0;
}