Stack with Array

Implement a stack data structure using an array. Read a sequence of commands and process them:

push X: push integer X onto the stack
pop: remove and print the top element, or print Empty if the stack is empty
peek: print the top element without removing it, or print Empty if the stack is empty

First line: an integer M (1 <= M <= 2·10^4), the number of commands
For each command:
- Line 1: command type (push, pop, or peek)
- Only for push, line 2: the integer X (-10^9 <= X <= 10^9)

For each pop or peek command, print one line: the value or Empty.

Input:
5
push
10
push
20
peek
pop
pop
Output:
20
20
10

Input:
3
pop
push
5
peek
Output:
Empty
5

Input:
5
push
1
push
2
pop
pop
pop
Output:
2
1
Empty

Once the stack is fully drained, further pop calls keep printing Empty.