Calculate Final Discounted Price

You are given a list of items. Each item has a price and a quantity. Your task is to calculate the total price and then apply a discount based on the following rules:

• If the total price \(T\) satisfies \(100 \le T < 200\), then a discount of 10% is applied.
• If \(200 \le T < 500\), then a discount of 20% is applied.
• If \(T \ge 500\), then a discount of 30% is applied.
• If none of the above conditions is met, no discount is applied.

Finally, compute the discounted price using the formula:

\(Final\ Price = \lfloor T \times (1 - discount) \rfloor\)

Note that all percentages should be considered in decimal form (for instance, 10% as 0.10). The input will be provided through standard input (stdin) and your answer should be printed to standard output (stdout).

inputFormat

The first line contains an integer n representing the number of items. Each of the following n lines contains two space-separated integers: the price and quantity of an item.

outputFormat

Output a single integer which is the final price after applying the discount.

The discount is applied based on the total price \(T\) as follows:

• If \(100 \le T < 200\), discount = 10%.
• If \(200 \le T < 500\), discount = 20%.
• If \(T \ge 500\), discount = 30%.
• Otherwise, discount = 0%.

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