class Solution {
    public int findLucky(int[] arr) {
        int[] result = new int[501];
        for(int i = 0; i < arr.length; i++){
            result[arr[i]]++;
        }
        for(int i = 500; i > 0; i--){
            if(result[i] == i) return i;
        }
        return -1;
    }
}