using System;

public class Program

{

    public static void Main()

    {

        string input;

        int vowel = 0;

        Console.WriteLine("Please enter a sentence: ");

        input = Console.ReadLine(); //sets the sentence the user enters to input

        input = input.ToLower(); //sets the sentence to all lowercase

        for (int i=0; i < input.Length; i++ ) //the integer "i" must be lower than the amount of characters in the string "input" for the loop to run 

        {

            if (input.Substring(i,1).Equals("a") || input.Substring(i,1).Equals("e") || input.Substring(i, 1).Equals("i") || input.Substring(i, 1).Equals("o") || input.Substring(i, 1).Equals("u")) //if the sentence has a,e,i,o or u, do the following below

            {

                vowel++; //adds 1 to the int "vowel"

            }

        }

        Console.WriteLine("There are " + vowel + "vowels in this sentence.");

    }

}