Simple Hash Table Implementation

You are required to implement a simple hash table that supports three operations: insert, delete, and search. The table is initially empty.

The operations are defined as follows:

• insert key value: Insert a key-value pair into the hash table. If the key already exists, update its value using the rule \( v_{new} = v_{old} + value \).
• delete key: Remove the key (and its corresponding value) from the hash table if it exists.
• search key: Print the value associated with the given key. If the key does not exist, print -1.

The input is read from standard input and the output is printed to standard output.

inputFormat

The first line contains an integer n (\(1 \leq n \leq 10^5\)) representing the number of operations. The next n lines describe the operations. Each operation is in one of the following forms:

• insert key value — where key is a string and value is an integer.
• delete key — where key is a string.
• search key — where key is a string.

outputFormat

For every search operation, output the result (the corresponding value or -1 if the key does not exist) on a new line.

## sample

4
insert apple 10
search apple
insert apple 5
search apple

10
15

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