------
## 最终结论
```python
def lengthLongestPath(input: str) -> int:
    max_length = 0
    path_length = {0: 0}
    
    for line in input.split('\n'):
        name = line.lstrip('\t')
        depth = len(line) - len(name)
        
        if '.' in name:
            max_length = max(max_length, path_length[depth] + len(name))
        else:
            path_length[depth + 1] = path_length[depth] + len(name) + 1
    
    return max_length
```