import java.util.Scanner;



public class Self {
	
	static int delka = 8000;
	static int pozice = 4000;

	static char pole[][] = new char[delka][delka];
	
	static int x = pozice;
	static int y = pozice;
	
	static int pocet = -1;
	
	public static boolean nahoru (int n) {
		y--;
		pocet++;
		//System.out.println("start: " + x + " = x : y = " + y);
		for (int i = y; i > y - n; i--) {
			if (pole[i][x] != '.') {
				pole[i][x] = '.';
			} else {
				System.out.println(pocet);
				return true;
			}
		}
		y -= n-1;	
		return false;
	}
	
	public static boolean dolu (int n) {
		y++;
		pocet++;
		//System.out.println("start: " + x + " = x : y = " + y);
		for (int i = y; i < y + n; i++) {
			if(pole[i][x] != '.') {
			pole[i][x] = '.';
			}else {
				System.out.println(pocet);
				return true;
			}
		}
		y += n;
		return false;
	}
	
	public static boolean vpravo (int n) {
		x++;
		pocet++;
		//System.out.println("start: " + x + " = x : y = " + y);
		for (int i = x; i < x + n; i++) {
			if(pole[y][i] != '.') {
			pole[y][i] = '.';
			} else{
				System.out.println(pocet);
				return true;
			}
		}
		x += n -1;
		return false;
	}
	
	public static boolean vlevo (int n) {
		y--;
		pocet++;
		//System.out.println("start: " + x + " = x : y = " + y);
		for (int i = x-1; i >= x - n; i--) {
			if(pole[y][i] != '.') {
				pole[y][i] = '.';
			} else {
				System.out.println(pocet);
				return true;
			}
		}
		x -= n;
		return false;

	}
	
	
	
	/*
	public static void vypis() {
		for (int i = 0; i < pole.length; i++) {
			for (int j = 0; j < pole.length; j++) {
				System.out.print(pole[i][j]);
			}
			System.out.println();
		}
		
	}*/
	
	
	public static void main(String[] args) {
		
		
		Scanner sc = new Scanner(System.in);
		
		boolean bre = false;
		
		while(sc.hasNextLine()) {
			
			int p = 0;
			
			int po = sc.nextInt();
			//System.out.println("nacetl: " + po);
			for (int i = 0; i < po; i++) {
				if (p == 0) {
					if (nahoru(sc.nextInt())) {
						bre = true;
						//System.out.println("skacu1");
						break;
					}
				} else if (p == 1) {
					if(vpravo(sc.nextInt())) {
						//System.out.println("skacu2");
						bre = true;
						break;
					}
				} else if (p == 2) {
					if(dolu(sc.nextInt())) {
						//System.out.println("skacu3");
						bre = true;
						break;
					}
				} else if (p == 3) {
					if(vlevo(sc.nextInt())) {
						//System.out.println("skacu4");
						bre = true;
						break;
					}
					p = -1;
				}
				p++;
			}
			//System.out.println();
			//System.out.println("pocet: " + po);
			if (bre == false) {
				System.out.println("OK");
			}
			pole = new char[delka][delka];
			
			x = pozice;
			y = pozice;
			pocet = -1;
			bre = false;
			//vypis();
			sc.nextLine();
		}
		
		
		/*
		nahoru(3);
		vpravo(1);
		dolu(1);
		vlevo(3);
		nahoru(2);
		vpravo(2);
		dolu(6);
		*/
		
		
		/*
		nahoru(2);
		vpravo(1);
		dolu(4);
		vlevo(4);
		nahoru(4);
		vpravo(3);
		*/
		
		//vypis();
		
		
		
		
		
	}
}