Untitled

class Solution:
    def maxGoodNumber(self, nums: List[int]) -> int:
        freq = [0] * 3
        p = []
        
        def permutation(curr):
            if len(curr) == 3:
                p.append(curr[:])
                return
            for i in range(3):
                if freq[i] == 1:
                    continue
                curr.append(nums[i])
                freq[i] = 1
                permutation(curr)
                freq[i] = 0
                curr.pop()
        permutation([])
        
        mx = 0
        for arr in p:
            bs = ""
            for e in arr:
                bs += bin(e)[2:] 
            mx = max(int(bs, 2), mx)  
        return mx