Two Strings - 2 hashset, and then, find the common element

TwoStrings6.cs

namespace Solution
{
using System;
using System.Text.RegularExpressions;
using System.Collections;    
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
        int val = int.Parse(Console.ReadLine());
        for(int i=0;i<val;i++)
            {
            char[] s1 = Console.ReadLine().Trim().ToCharArray();
            char[] s2 = Console.ReadLine().Trim().ToCharArray();
            HashSet<char> H1=new HashSet<char>();
			HashSet<char> H2=new HashSet<char>();
            //bool check = false;
           for(int x=0;x<s1.Length;x++)H1.Add(s1[x]);
		   for(int y=0;y<s2.Length;y++)H2.Add(s2[y]);
           bool chk=false;
		   foreach(char c in H1){
				if(H2.Contains(c))chk=true;
			}
			Console.WriteLine(chk?"YES":"NO");
            
           }
        }
    }
}