Problem: 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

Solution (in PYTHON3):

Solution:
# http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ITP2_2_A&lang=jp
# Stack

from collections import deque
import sys
input = sys.stdin.readline

def loop_proc():
    (n1,n2) = map(int,input().split())
    wl =[]
    for i in range(n1):
        wl.append(deque())
    for i in range(n2):
        l = list(map(int,input().split()))  
        if (l[0] == 0 ):
            wl[l[1]].append(l[2])
        elif (l[0] == 1 ):
            if ( len(wl[l[1]]) != 0 ):
                tl = wl[l[1]]
                print (tl[-1])
        elif (l[0] == 2 ):
            if ( len(wl[l[1]]) != 0 ):
                wl[l[1]].pop()
 

loop_proc()