class Solution:
    def largestTimeFromDigits(self, A: List[int]) -> str:
        A.sort(reverse=True)
        less3 = 0
        less5 = 0
        for x in A:
            if x <= 3:
                less3 += 1
            if x <= 5:
                less5 += 1

        if 2 in A and less3 >= 2 and less5 >= 3:
            m = [2,3,5,9]
        else:
            m = [1,9,5,9]

        res = []
        for i in range(4):
            for j in range(len(A)):
                if A[j] <= m[i]:
                    res.append(A[j])
                    A.pop(j)
                    break
            else:
                return ''

        s = ''.join(map(str,res))
        return s[:2] + ':' + s[2:]