import itertools
from typing import Iterator, Set

class NameGenerator:
    def __init__(self):
        self._name_iterator = self._create_iterator()
        self.used_names = set()
    
    def _create_iterator(self) -> Iterator[str]:
        """
        Generates obfuscated names like: vIl1lO0o0Z2z2...
        """
        patterns = ['Il1l', 'O0o0', 'Z2z2', 'S5s5', 'B8b8', 'Q9q9']
        for length in itertools.count(2):  # Start with length=2, continue forever
            for combo in itertools.product(patterns, repeat=length):
                yield 'v' + ''.join(combo)

    def generate_name(self) -> str:
        """
        Get a fresh unique variable name.
        """
        while True:
            candidate = next(self._name_iterator)
            if candidate not in self.used_names:
                self.used_names.add(candidate)
                return candidate