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)

from collections import deque
import sys

n, q = map(int, input().split())

Q = [deque() for _ in range(n)]
ans = []
# for _ in range(q):
#     query = list(map(int,sys.stdin.readline().split()))
# for query in (list(map(int,line.split())) for line in sys.stdin):
#     if query[0] == 0:Q[query[1]].append(query[2])
#     elif query[0] == 1 and Q[query[1]]:ans.append(Q[query[1]][0])
#     elif query[0] == 2 and Q[query[1]]:Q[query[1]].popleft()
for query in (line.split() for line in sys.stdin):
    t = int(query[1])
    if query[0] == '0':Q[t].append(query[2])
    elif query[0] == '1' and Q[t]:ans.append(Q[t][0])
    elif query[0] == '2' and Q[t]:Q[t].popleft()

for i in ans:
    print(i)