Stack

Stack is a container of elements that are inserted and deleted according to LIFO (Last In First Out).

For $n$ stack $S_i$ ($i = 0, 1, ..., n-1$), perform a sequence of the following operations.

• push($t$, $x$): Insert an integer $x$ to $S_t$.
• top($t$): Report the value which should be deleted next from $S_t$. If $S_t$ is empty, do nothing.
• pop($t$): Delete an element from $S_t$. If $S_t$ is empty, do nothing.

In the initial state, all stacks are empty.

Constraints

• $1 \leq n \leq 1,000$
• $1 \leq q \leq 200,000$
• $-1,000,000,000 \leq x \leq 1,000,000,000$

Input

The input is given in the following format.

$n \; q$ $query_1$ $query_2$ : $query_q$

Each query $query_i$ is given by

0 $t$ $x$

or

1 $t$

or

2 $t$

where the first digits 0, 1 and 2 represent push, top and pop operations respectively.

Output

For each top operation, print an integer in a line.

Example

Input

3 9 0 0 1 0 0 2 0 0 3 0 2 4 0 2 5 1 0 1 2 2 0 1 0

Output

3 5 2

inputFormat

Input

The input is given in the following format.

$n \; q$ $query_1$ $query_2$ : $query_q$

Each query $query_i$ is given by

0 $t$ $x$

or

1 $t$

or

2 $t$

where the first digits 0, 1 and 2 represent push, top and pop operations respectively.

outputFormat

Output

For each top operation, print an integer in a line.

Example

Input

3 9 0 0 1 0 0 2 0 0 3 0 2 4 0 2 5 1 0 1 2 2 0 1 0

Output

3 5 2

样例

3 9
0 0 1
0 0 2
0 0 3
0 2 4
0 2 5
1 0
1 2
2 0
1 0

3
5
2

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