Problem:
Queue

Queue is a container of elements that are inserted and deleted according to FIFO (First In First Out).

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

enqueue($t$, $x$): Insert an integer $x$ to $Q_t$.

front($t$): Report the value which should be deleted next from $Q_t$. If $Q_t$ is empty, do nothing.

dequeue($t$): Delete an element from $Q_t$. If $Q_t$ is empty, do nothing.

In the initial state, all queues are empty.

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 enqueue, front and dequeue operations respectively.

Output

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

Constraints

$1 \leq n \leq 1,000$

$1 \leq q \leq 200,000$

$-1,000,000,000 \leq x \leq 1,000,000,000$

Sample Input 1

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

Sample Output 1

1
4
2

Solution in C (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>


#define	ll_int	long long int


typedef struct{
	int front;
	int rear;
} QUEUE_T;


ll_int **QUEUE, *S_QUEUE;
QUEUE_T *QP;	// キューのフロント、リアを管理する配列


// キューの初期化
void  Init(int n)
{
	int i;

	for(i = 0; i < n; i++)
		QP[i].front = QP[i].rear = 0;
}


void Enqueue(int t, int x, int size)
{
	QUEUE[t][(QP[t].rear++) % size] = x;
}


void Front(int t, int size)
{
	if(QP[t].front != QP[t].rear)
		printf("%lld\n", QUEUE[t][(QP[t].front) % size]);
}


void Dequeue(int t, int size)
{
	if(QP[t].front != QP[t].rear)
		QP[t].front++;
}


int main()
{
	int n, q;
	int size;
	int query, t;
	ll_int x;
	int i;

	scanf("%d %d", &n, &q);

	if(q > n)
		size = q;
	else
		size = n;

	S_QUEUE = (ll_int *)malloc(sizeof(ll_int) * n * size);
	QUEUE = (ll_int **)malloc(sizeof(ll_int *) * n);
	for(i = 0; i < n; i++)
		QUEUE[i] = S_QUEUE + (i * size);
	QP = (QUEUE_T *)malloc(sizeof(QUEUE_T) * n);

	Init(n);

	for(i = 0; i < q; i++){
		scanf("%d", &query);

		if(query == 0){
			scanf("%d %lld", &t, &x);
			Enqueue(t, x, size);
		}else if(query == 1){
			scanf("%d", &t);
			Front(t, size);
		}else if(query == 2){
			scanf("%d", &t);
			Dequeue(t, size);
		}
	}

	return 0;
}

/*
	enqueue(t, x): Qtに整数xを挿入する。
	front(t): Qtから次に取り出される要素を報告する。ただし、Qtが空の場合は何もしない。
	dequeue(t): Qtから要素を取り出し削除する。ただし、Qtが空の場合は何もしない。

*/