Make it anagram - using Dictionary, Hashset - more generic approach

MakeItAnagram2.cs

using System;
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 */
        
        string A=Console.ReadLine();
        string B=Console.ReadLine();
        
        HashSet<char> hashSet=new HashSet<char>();
        
        foreach (char c in A){
            hashSet.Add(c);
        }
        
        foreach (char c in B){
            hashSet.Add(c);
        }
        
        Dictionary<char,int> dic1=new Dictionary<char,int>();
        Dictionary<char,int> dic2=new Dictionary<char,int>();
        
        foreach (char c in hashSet){
            dic1.Add(c,0);
            dic2.Add(c,0);
        }
        
        foreach (char c in A){  
            dic1[c]++;            
        }
        
        foreach (char c in B){  
            dic2[c]++;            
        }
        
        int rez=0;
        
        foreach (char c in hashSet){  
            rez+=Math.Abs(dic1[c]-dic2[c]);       
        }
        
        Console.WriteLine(rez);
    }
}