Implement Stack using Linked List.

Input:

• The First line of the input contains an integer N denoting the number of test cases.
• The Second line of the input contains an integer N denoting the number of operations

• Then for each input line of operation has the following format:

  P <element>        Insert into stack
  O                  Delete from stack
  S          Number of elements in stack
  I          Checks if stack is Empty     
  T          Returns Top element

Constraints

• 1 <= N <= 20

Sample Input:

    1
    10
    P 1
    P 2 
    S
    O
    O
    I
    S
    T
    P 10
    S

Sample Output:

    1 
    2 1 
    2
    2
    1 
    1

    True
    0
    Stack Empty Exception
    None
    10 
    1