Inventory Management System

You are required to design an inventory management system. The system processes a series of commands to manage a stock of products. Each command can be one of the following:

• add product_id quantity: Increase the inventory of the product identified by product_id by quantity.
• remove product_id quantity: Decrease the inventory of the product identified by product_id by quantity. However, the inventory should not drop below zero. In other words, the new inventory is computed as \( \max(0, \text{current_inventory} - \text{quantity} ) \).
• get product_id: Output the current quantity for the product identified by product_id.

The commands are processed in order. Only the outputs from the "get" commands should be printed.

inputFormat

The first line of the input contains an integer n representing the number of commands. The following n lines each contain a command, which is one of the following formats:

• add product_id quantity
• remove product_id quantity
• get product_id

outputFormat

For each "get" command in the order they appear, output the corresponding product quantity on a new line.

## sample

6
add 101 50
add 102 20
remove 101 10
get 101
remove 102 30
get 102

40
0

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