#
# 
# @param arr int整型一维数组 the array
# @return int整型
#
class Solution:
    def maxLength(self , arr ):
        # write code here
        f=l=0
        max_len = 0
        if(len(arr)<2):
            return len(arr)
        while f+1 < len(arr):
            if(arr[f+1] not in arr[l:f+1]):
                f += 1
                max_len = max(max_len,f-l+1)
            else:
                l += 1
        return max_len