using System.Collections.Generic;
public static void Main()
Console.WriteLine(LargestNumberOccur(a));
public static int LargestNumberOccur(int[] a)
Dictionary<int, int> dict = new Dictionary<int, int>();
HashSet<int> hashSet = new HashSet<int>();
for (int i = 0; i < a.Length; i++) {
if (dict.ContainsKey(a[i])) {
if (dict[a[i]] == a[i]) {
} else if (dict[a[i]] > a[i]) {
foreach (int item in hashSet) {
result = Math.Max(result, item);