Description

Please complete the previous question first!

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請先完成上一題!

Please write the following two functions:

請撰寫以下兩個函式：

int StackTop(Stack* obj): Return the value of the top node of the Stack.

int StackTop(Stack* obj)：請回傳Stack最上方節點的值。

int StackBottom(Stack* obj): Return the value of the bottom node of the Stack.

int StackButtom(Stack* obj)：請回傳Stack最底下節點的值。

Input

Input consists of multiple lines until EOF, each line contains the command (and required parameters).

輸入包含多行，直到EOF為止，每行包含要做的指令(以及需要的參數)。

For example: push 10, pop, printTop, printButtom.

例如：push 10, pop, printTop, printButtom。

Output

Refer to Description.

請參考 Description。

Sample Input 1

push 1
push -7
pop
push 1
push 22
printTop
pop
printButtom
printTop
push 7
push 45
push 17
printTop
push -10
printButtom
pop
pop
printTop

Sample Output 1

22
1
1
17
1
45

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