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# Buy and Sell n-times
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## Goal
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Given is the price-development of an arbitrary stock.
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Suppose you have perfect knowledge and are able to buy and sell the stock **multiple times**.
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Write an algorithm that outputs the maximum profit that can be made by exactly n sales.
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* The price-development is given for an arbitrary number of days.
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* A stock can only be sold on the next day.
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* Stock-prices are given as integers
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* **Each buy must be made on another date after the previous sale**
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### Input
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A blank-separated array of numbers.
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The first number is the number of sales allowed.
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All following numbers are stock-prices.
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Each position symbolises the stock-price of a given day.
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### Output
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The maximum profit that can be made within that period by `n` sales.
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### Constraints
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* 2 <= `n` <= 10
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* 2 * `n` <= `days with stock-prices` <= 50
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* 1 <= `stock-price` <= 2,147,483,647
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### Example
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**Input:**
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`3 12 11 13 9 12 8 14 13 15`
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where `n` is `3`
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**Output:**
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`12`
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