import java.util.*;


public class Solution {
    /**
     * 
     * @param arr int整型一维数组 the array
     * @return int整型
     */
    public int maxLength (int[] arr) {
        // write code here
        ArrayList<Integer> temp = new ArrayList<>();
        int max = 0;
        ArrayList<Integer> maxList = new ArrayList<>();
        for(int i = 0;i<arr.length;i++){
            if(temp.contains(arr[i])){
                while(true){
                    Integer next = temp.remove(0);
                    if(next == arr[i]){
                        break;
                    }
                }
            }
            temp.add(arr[i]);
            max = Math.max(max,temp.size());

        }
        return max;
    }
}