<p>You are given the string <code>croakOfFrogs</code>, which represents a combination of the string <code>&quot;croak&quot;</code> from different frogs, that is, multiple frogs can croak at the same time, so multiple <code>&quot;croak&quot;</code> are mixed.</p>

<p><em>Return the minimum number of </em>different<em> frogs to finish all the croaks in the given string.</em></p>

<p>A valid <code>&quot;croak&quot;</code> means a frog is printing five letters <code>&#39;c&#39;</code>, <code>&#39;r&#39;</code>, <code>&#39;o&#39;</code>, <code>&#39;a&#39;</code>, and <code>&#39;k&#39;</code> <strong>sequentially</strong>. The frogs have to print all five letters to finish a croak. If the given string is not a combination of a valid <code>&quot;croak&quot;</code> return <code>-1</code>.</p>

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

<pre>
<strong>Input:</strong> croakOfFrogs = &quot;croakcroak&quot;
<strong>Output:</strong> 1 
<strong>Explanation:</strong> One frog yelling &quot;croak<strong>&quot;</strong> twice.
</pre>

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

<pre>
<strong>Input:</strong> croakOfFrogs = &quot;crcoakroak&quot;
<strong>Output:</strong> 2 
<strong>Explanation:</strong> The minimum number of frogs is two. 
The first frog could yell &quot;<strong>cr</strong>c<strong>oak</strong>roak&quot;.
The second frog could yell later &quot;cr<strong>c</strong>oak<strong>roak</strong>&quot;.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> croakOfFrogs = &quot;croakcrook&quot;
<strong>Output:</strong> -1
<strong>Explanation:</strong> The given string is an invalid combination of &quot;croak<strong>&quot;</strong> from different frogs.
</pre>

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

<ul>
	<li><code>1 &lt;= croakOfFrogs.length &lt;= 10<sup>5</sup></code></li>
	<li><code>croakOfFrogs</code> is either <code>&#39;c&#39;</code>, <code>&#39;r&#39;</code>, <code>&#39;o&#39;</code>, <code>&#39;a&#39;</code>, or <code>&#39;k&#39;</code>.</li>
</ul>

class Solution:
    def minNumberOfFrogs(self, croakOfFrogs: str) -> int:
        frogs={'c':0, 'r':0, 'o':0, 'a':0}
        croak = "croak"
        cur_frogs = 0
        frog_num = 0
        for c in croakOfFrogs:
            if c in frogs:
                frogs[c] += 1
                if c != 'c':
                    if frogs[croak[croak.index(c) - 1]] <= 0:
                        return -1
                    frogs[croak[croak.index(c) - 1]] -=1
                else:
                    cur_frogs += 1
                    frog_num = max(cur_frogs, frog_num)
            elif c == 'k':
                if frogs['a'] <= 0:
                    return -1
                frogs['a'] -= 1
                cur_frogs -= 1
            else:
                return -1
        if cur_frogs > 0:
            return -1
        return frog_num

        # croak = "croak"
        # frogs = []
        # max_f = 0
        # for c in croakOfFrogs:
        #     if c == 'c':
        #         frogs.append(0)
        #     else:
        #         found = False
        #         for i in range(len(frogs)):
        #             if croak[frogs[i] + 1] == c:
        #                 frogs[i] += 1
        #                 found = True
        #                 if frogs[i] == len(croak) - 1:
        #                     frogs.pop(i)
        #                 break
        #         if not found:
        #             return -1
        #     if len(frogs) > max_f:
        #         max_f = len(frogs)
        # if len(frogs) != 0:
        #     return -1
        # return max_f
            
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