import java.util.*;
import java.lang.*;
import java.io.*;

class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner in = new Scanner(System.in);
		int[][] x = new int[2001][2001];
		int n = in.nextInt();
		int move;
		int xPos=1001, yPos=1001;
		for(int i = 0; i < n; i++) {
			move = in.nextInt();
			if(x[xPos][yPos] == 1) { 
            	System.out.print(i);
            	return;
        	}
        	else x[xPos][yPos]=1;
	        if(move == 1) {
	            xPos--;
	            yPos++;
	        }
	        if(move == 2) {
	            yPos++;
	        }
	        if(move == 3) {
	            xPos++;
	            yPos++;
	        }
	        if(move == 4) {
	            xPos++;
	        }
	        if(move == 5) {
	            xPos++;
	            yPos--;
	        }
	        if(move == 6) {
	            yPos--;
	        }
	        if(move == 7) {
	            xPos--;
	            yPos--;
	        }
	        if(move == 8) {
	            xPos--;
	        }
		}
		System.out.print("Ok" + "\n" + (Math.abs(xPos-1001)+Math.abs(yPos-1001)));
	}
}