### wordCount 
from typing import *
def f_gold(startWords: List[str], targetWords: List[str]) -> int:
    s = set()
    for word in startWords:
        mask = 0
        for c in word:
            mask |= 1 << (ord(c) - ord('a'))
        s.add(mask)
    ans = 0
    for word in targetWords:
        mask = 0
        for c in word:
            mask |= 1 << (ord(c) - ord('a'))
        for c in word:
            t = mask ^ (1 << (ord(c) - ord('a')))
            if t in s:
                ans += 1
                break
    return ans