class Solution:
    def findLUSlength(self, 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)
        res = -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:
                res = max(res, len(strs[i]))
        return res