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 CPP):

Solution:
//Assalamualaikum//
//Mahmudul Ahsan Mahi
//RUET CSE 19'


#include<iostream>
#include<cstdio>
#include <bits/stdc++.h>
#include<cstring>
#include<vector>
#include<list>
#include<stack>
#include<iterator>
#include<algorithm>
#include<cstdlib>

#define ll long long
#define ull unsigned long long
#define pi acos(-1)

using namespace std;

int main()
{
    stack<int>st[1001];

    int i, n, q, o, t, x;

    cin>>n>>q;

    while(q--){
        cin>>o;

        if(o==0){
            cin>>t>>x;
            st[t].push(x);
        }

        else if(o==1){
            cin>>t;
            if(st[t].empty())
                ;
            else{
                cout<<st[t].top()<<endl;
            }
        }

        else if(o==2){
            cin>>t;
            if(st[t].empty())
                ;
             else{
                st[t].pop();
             }


        }
    }


    return 0;
}