<p>There are <code>numBottles</code> water bottles that are initially full of water. You can exchange <code>numExchange</code> empty water bottles from the market with one full water bottle.</p>

<p>The operation of drinking a full water bottle turns it into an empty bottle.</p>

<p>Given the two integers <code>numBottles</code> and <code>numExchange</code>, return <em>the <strong>maximum</strong> number of water bottles you can drink</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/07/01/sample_1_1875.png" style="width: 500px; height: 245px;" />
<pre>
<strong>Input:</strong> numBottles = 9, numExchange = 3
<strong>Output:</strong> 13
<strong>Explanation:</strong> You can exchange 3 empty bottles to get 1 full water bottle.
Number of water bottles you can drink: 9 + 3 + 1 = 13.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/07/01/sample_2_1875.png" style="width: 500px; height: 183px;" />
<pre>
<strong>Input:</strong> numBottles = 15, numExchange = 4
<strong>Output:</strong> 19
<strong>Explanation:</strong> You can exchange 4 empty bottles to get 1 full water bottle. 
Number of water bottles you can drink: 15 + 3 + 1 = 19.
</pre>

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

<ul>
	<li><code>1 &lt;= numBottles &lt;= 100</code></li>
	<li><code>2 &lt;= numExchange &lt;= 100</code></li>
</ul>

class Solution:
    def numWaterBottles(self, numBottles: int, numExchange: int) -> int:
        full = numBottles
        empty = 0
        out = 0
        while not (full == 0 and empty < numExchange):
            out += full
            empty += full
            full = empty//numExchange
            empty = empty%numExchange
        return out
16500