#
# 
# @param arr int整型一维数组 the array
# @return int整型
#
class Solution:
    def maxLength(self , arr ):
        # write code here
        li = []
        ret = 0
        for i in arr:
            if i in li:
                ret = max(ret, len(li))
                start = li.index(i)
                li = li[start+1:]
            li.append(i)
        return max(ret, len(li))