### findLUSlength 
from typing import *
def f_gold(strs: List[str]) -> int:
    def check(a, b):
        i = j = 0
        while i < len(a) and j < len(b):
            if a[i] == b[j]:
                j += 1
            i += 1
        return j == len(b)
    n = len(strs)
    ans = -1
    for i in range(n):
        j = 0
        while j < n:
            if i == j or not check(strs[j], strs[i]):
                j += 1
            else:
                break
        if j == n:
            ans = max(ans, len(strs[i]))
    return ans