题目描述
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.
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 enqueue, front and dequeue operations respectively.
Output
For each front 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
1
4
2
输入格式
见题面
输出格式
见题面
样例输入
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
样例输出
1
4
2