Warehouse Inventory Management

You are given an initial warehouse inventory and a series of operations. The inventory is represented by a set of categories each with an associated count. The operations are of three types:

• add: Increase the inventory count for a given category by a specified amount. If the category does not exist, add it with the given count.
• update: Set the inventory count of a given category to the specified amount (regardless of whether it already exists).
• retrieve: Output the current count for the given category. If the category does not exist, output 0 (i.e. \(0\)).

Process the operations in the order they appear. For each retrieve operation, output the current count on a separate line.

Note: If a category is not present in the inventory, its count is considered \(0\).

inputFormat

The input is read from standard input (stdin) and has the following format:

1. An integer n representing the number of inventory items.
2. n lines follow, each containing a category name (a string) and an integer representing the count.
3. An integer m representing the number of operations.
4. m lines follow, each describing an operation in one of the following formats:
   • add <category> <value>
   • update <category> <value>
   • retrieve <category>

outputFormat

For each retrieve operation, output the current count for the specified category on a new line.

## sample

1
electronics 50
1
retrieve electronics

50

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