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 Python3 (judge verdict: Accepted)

# AOJ ITP2_2_B: Queue
# Python3 2018.6.24 bal4u

from collections import deque
n, q = map(int, input().split())
Q = []
for i in range(n): Q.append(deque())
for i in range(q):
	a = input().split()
	t = int(a[1])
	if   a[0] == '0': Q[t].append(a[2])        # push
	elif a[0] == '1' and Q[t]: print(Q[t][0])  # front
	elif a[0] == '2' and Q[t]: Q[t].popleft()  # dequeue