题目描述
For a dictionary $M$ that stores elements formed by a pair of a string key and an integer value, perform a sequence of the following operations. Note that each key in $M$ must be unique.
- insert($key$, $x$): Insert an element formed by a pair of $key$ and $x$ to $M$.
- get($key$): Print the value with the specified $key$. Print 0 if there is no such element.
- delete($key$): Delete the element with the specified $key$.
Constraints
- $1 \leq q \leq 200,000$
- $1 \leq x \leq 1,000,000,000$
- $1 \leq$ length of $key$ $\leq 20$
- $key$ consits of lower case letters
Input
The input is given in the following format.
$q$
$query_1$
$query_2$
:
$query_q$
Each query $query_i$ is given by
0 $key$ $x$
or
1 $key$
or
2 $key$
where the first digits 0, 1 and 2 represent insert, get and delete operations respectively.
Output
For each get operation, print an integer in a line.
Example
Input
8
0 blue 4
0 red 1
0 white 5
1 red
1 blue
2 red
1 black
1 red
Output
1
4
0
0
输入格式
见题面
输出格式
见题面
样例输入
8
0 blue 4
0 red 1
0 white 5
1 red
1 blue
2 red
1 black
1 red
样例输出
1
4
0
0