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 C++ (judge verdict: Accepted)

#include<iostream>
#include<map>
#include<algorithm>
using namespace std;
int main()
{
	int n;
	cin >> n;
	map<string, int> p;
	string color;
	int value;

	while (n--)
	{
		int type;
		cin >> type;
		
		switch (type)
		{
		case 0:
			cin >> color >> value;
			p[color] = value;
			break;
		case 1:
			cin >> color;
			if (p.count(color) != 0)cout << p[color] << endl;
			else cout << 0 << endl;
			break;
		case 2:
			cin >> color;
			map<string, int>::iterator temp = p.find(color);
			if(temp!=p.end())p.erase(temp);
			break;
		}
	}
}