using System;
using System.Text;
using System.Linq;
using System.Collections.Generic;

class Solution {
    public static string[] getFrequencies(string textString) {
        Dictionary<string, int> words = new Dictionary<string, int>();
        StringBuilder curr = new StringBuilder();
        for (int i = 0; i < textString.Length; i++) {
            if (!Char.IsLetter(textString[i])) {
                if (curr.Length != 0) {
                    string s = curr.ToString();
                    if (!words.ContainsKey(s)) {
                        words.Add(s, 1);
                    } else {
                        words[s]++;
                    }
                    curr.Clear();
                }
            } else {
                curr.Append(char.ToLower(textString[i]));
            }
        }
        if (curr.Length != 0) {
            string s = curr.ToString();
            if (!words.ContainsKey(s)) {
                words.Add(s, 1);
            } else {
                words[s]++;
            }
        }

        List<string> w = new List<string>();
        foreach (string s in words.Keys) {
            w.Add(s);
        }
        w.Sort();

        string[] ret = new string[words.Count];
        for (int i = 0; i < w.Count; i++) {
            ret[i] = w[i] + " " + words[w[i]];
        }

        return ret;
    }
}

class Program
{
    static void Main(string[] args)
    {
        string textString = "FirstWord, sECONDwORD, A B A";
        string[] output = Solution.getFrequencies(textString);
        string[] expected = new string[]{"a 2", "b 1", "firstword 1", "secondword 1"};

        Console.WriteLine("Your output: [{0}]", string.Join(", ", output));
        Console.WriteLine("Expected output: [{0}]", string.Join(", ", expected));
    }
}