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.Scanner;
import java.util.TreeMap;

public class Main {
	public static void main(String[] args){
		int i, q, order;
		String key;
		TreeMap<String, Integer> tm = new TreeMap<String, Integer>();
		try (Scanner sc = new Scanner(System.in)) {
			q = sc.nextInt();
			for(i = 0; i < q; i++) {
				order = sc.nextInt();
				key = sc.next();
				if(order == 0) {
					tm.put(key, sc.nextInt());
				}else if(order == 1) {
					if(tm.get(key) == null) {
						System.out.println(0);
					}else {
						System.out.println(tm.get(key));
					}
				}else {
					tm.remove(key);
				}
			}
		}
	}
}