using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

    //https://edabit.com/challenge/5ytLyHsZHfyDhBgXr

    public static int CountVowels(string str) 

    {

      int count = 0;

            foreach(char letter in str)

            {

                if(letter.Equals('a') || letter.Equals('e') || letter.Equals('i')|| letter.Equals('o')|| letter.Equals('u'))

                {

                    count++;

                }

            }

            return count;

    }

}