public static string happyLadybugs(string b)
    {
        Dictionary<char,int> map = new Dictionary<char,int>();
        // Case for checking if string contains all "_"
        bool checkUnderScore = false; 
        bool containsUnderScore  = false;
        for(int i=0;i<b.Length;i++)
        {
            if(b[i]>='A' && b[i] <= 'Z')
            {
                checkUnderScore = true;
                
            }
            else
            {
               containsUnderScore = true; 
            } 
            
        }
        if(checkUnderScore == false)
        {
            return "YES";
        }
        if(containsUnderScore==false)
        {
            int left=0;
            int right=0;
           for(int i=1;i<b.Length-1;i++)
           {
               left = i-1;
               right= i+1;
               if(b[left] != b[i] && b[right] != b[i])
               {
                   return "NO";
               }
           } 
        }
        // Other Cases
        for(int i=0;i<b.Length;i++)
        {
            if(map.ContainsKey(b[i]))
            {
                map[b[i]]++;
            }
            else
            {
                map[b[i]] = 1;
            }
        }      
        foreach(var item in map)
        {
            if(item.Key!='_' && item.Value == 1)
            {
                return "NO";
            }
        }
        return "YES";
    }