Ttykuu

Probably all of us remember a game called Snake, where you have to eat as many apples as you can. As you may guess your task is to write a program which determines whether our snake wins the game or it ends up eating itself. Snake moves along an infinitely large board. It can turn left, right or go straight. Also, the snake - when going straight - can eat an apple under the condition it is in front of him. If such a scenario occurs our friend extends onto a cell where the meal took place. The initial snake length is 1.

Input:

The first line of the input contains the number of tests t (t < 1001). Each of the next t lines consists of an integer n (n < 2401) and n characters describing snake's movements. Each character is one of four letters: 'L', 'R', 'F' or 'E'. 'L' - snake goes on the field on his left, 'R' - snake goes right, 'F' - snake goes on the field in front of him, 'E' - as previous but with eating an apple.

Output:

For each test, you should print YES if the snake survives the whole game without dying or otherwise print the number of the step in which the snake bites itself.

Example

Input:

2

6 FLERFF

8 EEEELLLL

Output:

YES

7

I have tried it a lot but unable to implement the correct logic, please help me. Thanks.

import java.util.LinkedList;
import java.util.Scanner;
public class SnakePuzzle 

private static Coordinates coordinates;
private static Scanner scan;
public static void main(String [] args) 
try 
scan = new Scanner(System.in);
int t=scan.nextInt();
for(int i=0;i<t;i++)
 if(scan.hasNext())
 int n=scan.nextInt();
 String s=scan.next();

 checkSnake(n,s);

 
 
 catch (Exception e) 
 
 

 public static void checkSnake(int n, String s) 
 LinkedList<Coordinates> l=new LinkedList<>();
 Coordinates c=new Coordinates(0, 0);
 l.addFirst(c);
 int count=0;
 for(int i=0;i<s.length();i++) 
 if(s.charAt(i)=='E') 
 Coordinates c1=new Coordinates(0, 1);
 l.addFirst(c1);
 count++;
 
 if(s.charAt(i)=='F') 
 l.removeLast();
 Coordinates c1=new Coordinates(0, 1);
 l.addFirst(c1);
 count++;
 
 if(s.charAt(i)=='L') 
 l.removeLast();
 Coordinates c1=new Coordinates(-1, 0);
 l.addFirst(c1);
 count++;
 
 if(s.charAt(i)=='F') 
 l.removeLast();
 Coordinates c1=new Coordinates(1, 0);
 l.addFirst(c1);
 count++;
 
 if(l.contains(c)) 
 System.out.println(count);
 
 
 if(count==n) 
 System.out.println("yes");
 

 
 

 class Coordinates
 int x;
 int y;

 Coordinates(int x, int y)
 this.x =x;
 this.y =y;
 

 public int getX() 
 return x;
 

 public void setX(int x) 
 this.x = x;
 

 public int getY() 
 return y;
 

 public void setY(int y) 
 this.y = y;