using System;

// To execute C#, please define "static void Main" on a class
// named Solution.

// "abc", "xyz" -> false
// "abc", "xyza" -> true
// "a", "a" -> true
// "aabbcc", "defa" -> true

// "aaa1millioncharacters.." , "xyz"
// "xyz", "aaa1millioncharacters.." 


class Solution
{
    bool HasCommon(string a, string b)
    {
        HashSet<char> set = new HashSet<char>();
        foreach (char c in a)
        {
            set.TryAdd(c);
        }

        foreach (char c in b)
        {
            if (set.HasKey(c))
            {
                return true;
            }
        }

        return false;
    }
}


// 6 -> "six"

// 42 -> "forty two"

// 8379 -> "eight thousand three hundred seventy nine".

// 32 million 


//0 -> "zero", 1-> "one", 2-> "two", .., 9-> "nine"
//11->"eleven", 12-> "...", 19 -> "nineteen"
// 10->"ten", ..., "90" -> "ninty"
// 100 -> "hundred"
// 1000 -> "thousand"

// (21 / 10) * 10 = 20
// 21 % 10 = 1 

// (101 / 100) * 100 = 100 (hundred)

// 101 % 100 = 1 -> 

// -25.138.379

string ConvertNumber(int number)
{
    Dictionary<int, string> numberDict = new Dictionary<int, string>()
    {
        { 0,  "zero" },
        ...
        { 100,  " hundred " },
        { 1000,  " thousand " },
        { 1000000, " million" },
    };

    string strNumber = "negative ";

    if (numberDict.ContainsKey(number))
    {
        strNumber = numberDict[number];
    }
    else
    {
        if (number > 1000000)
        {
            var (s ,n) = Part(number, 1000000, " million ");
            strNumber += s;
            number = n;
        }
        // 25 million
        // 138.379
        if (number > 1000)
        {
            var (s ,n) = Part(number, 1000, " thousand ");
            strNumber += s;
            number = n;
        }
        // twenty five million one hundred thirty eight thousand
        // 379

        if (number > 100)
        {
            var (s ,n) = Part(number, 100, " hundred ");
            strNumber += s;
            number = n;
        }
        // twenty five million one hundred thirty eight thousand three hundred
        // 79

        int a = (number / 10) * 10; // 20
        strNumber += numberDict[a];
        int b = number % 10; // 1
        strNumber += numberDict[b];
    }

    return strNumber;
}

(string, int) Part(int number, int divider, string unit)
{
    int part = number / divider; // 8379
    string strNumber = ConvertNumber(part) + unit;
    int remainingNumber = number - part * divider;
    return (strNumber, remainingNumber);
}