Problem:
Map: Delete

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 $key$.

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.

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

Sample Input 1

8
0 blue 4
0 red 1
0 white 5
1 red
1 blue
2 red
1 black
1 red

Sample Output 1

1
4
0
0

Solution in JAVA (judge verdict: Accepted)

import java.util.*;
import java.io.*;
public class Main {

	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		PrintWriter out=new PrintWriter(System.out);
		TreeMap<String,Integer> map=new TreeMap<>();
		int q=Integer.parseInt(in.next());
		for(int i=0;i<q;i++) {
			int odr=Integer.parseInt(in.next());
			
			switch(odr) {
			case 0:
				String key0=in.next();
				int x0=Integer.parseInt(in.next());
				map.put(key0,x0);
				break;
				
			case 1:
				String key1=in.next();
				Integer num1=map.get(key1);
				out.println((num1!=null)? num1:0);
				break;
				
			case 2:
				String key2=in.next();
				map.remove(key2);
				break;
			}
		}
		out.flush();
	}

}