<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:
        # Dictionary to keep track of the count of each character
        char_count = {'c': 0, 'r': 0, 'o': 0, 'a': 0, 'k': 0}
        
        # Variable to keep track of the minimum number of frogs needed at any point in time
        frogs_needed = 0
        
        # Variable to keep track of the maximum number of frogs needed at any point in time
        max_frogs = 0
        
        # Iterate through each character in the string
        for char in croakOfFrogs:
            # Increment the count of the current character
            char_count[char] += 1
            
            # If the current character is 'c', increment frogs_needed
            if char == 'c':
                frogs_needed += 1
            # If the current character is 'k', decrement frogs_needed
            elif char == 'k':
                frogs_needed -= 1
            
            # Check if the sequence of characters is valid
            if not (char_count['c'] >= char_count['r'] >= char_count['o'] >= char_count['a'] >= char_count['k']):
                return -1
            
            # Update max_frogs with the maximum value of frogs_needed seen so far
            max_frogs = max(max_frogs, frogs_needed)
        
        # Check if all frogs have completed their croak
        if char_count['c'] == char_count['r'] == char_count['o'] == char_count['a'] == char_count['k']:
            return max_frogs
        else:
            return -1

# Example usage:
solution = Solution()
croakOfFrogs = "croakcroak"
print(solution.minNumberOfFrogs(croakOfFrogs))  # Output: 1
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