------
## 最终结论
```python
from collections import deque

def wordLadderLength(beginWord, endWord, wordList):
    if endWord not in wordList:
        return 0
    
    # Initialize the queue for BFS
    queue = deque([(beginWord, 1)])  # (current_word, current_length)
    
    while queue:
        current_word, current_length = queue.popleft()
        
        # Try changing each letter in the current word
        for i in range(len(current_word)):
            for c in 'abcdefghijklmnopqrstuvwxyz':
                new_word = current_word[:i] + c + current_word[i+1:]  # Create new word by changing one letter
                
                if new_word == endWord:
                    return current_length + 1  # Found the endWord
                
                if new_word in wordList:
                    queue.append((new_word, current_length + 1))  # Add new word to the queue
                    wordList.remove(new_word)  # Remove from list to avoid revisiting

    return 0  # No transformation found
```