Most Expensive Item That Can Not Be Bought
<p>You are given two <strong>distinct</strong> <strong>prime</strong> numbers <code>primeOne</code> and <code>primeTwo</code>.</p>

<p>Alice and Bob are visiting a market. The market has an <strong>infinite</strong> number of items, for <strong>any</strong> positive integer <code>x</code> there exists an item whose price is <code>x</code>. Alice wants to buy some items from the market to gift to Bob. She has an <strong>infinite</strong> number of coins in the denomination <code>primeOne</code> and <code>primeTwo</code>. She wants to know the <strong>most expensive</strong> item she can <strong>not</strong> buy to gift to Bob.</p>

<p>Return <em>the price of the <strong>most expensive</strong> item which Alice can not gift to Bob</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> primeOne = 2, primeTwo = 5
<strong>Output:</strong> 3
<strong>Explanation:</strong> The prices of items which cannot be bought are [1,3]. It can be shown that all items with a price greater than 3 can be bought using a combination of coins of denominations 2 and 5.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> primeOne = 5, primeTwo = 7
<strong>Output:</strong> 23
<strong>Explanation:</strong> The prices of items which cannot be bought are [1,2,3,4,6,8,9,11,13,16,18,23]. It can be shown that all items with a price greater than 23 can be bought.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt; primeOne, primeTwo &lt; 10<sup>4</sup></code></li>
	<li><code>primeOne</code>, <code>primeTwo</code> are prime numbers.</li>
	<li><code>primeOne * primeTwo &lt; 10<sup>5</sup></code></li>
</ul>
Math; Dynamic Programming; Number Theory
impl Solution {
    pub fn most_expensive_item(prime_one: i32, prime_two: i32) -> i32 {
        prime_one * prime_two - prime_one - prime_two
    }
}
