using System;

public class Program

{

    public static void Main()

    {

        string input = Console.ReadLine();

int sum = 0;

for (int i = 0; i < input.Length; i++)

{

        switch (input[i])

        {

        case 'e': sum += 1; break;

         }

}

Console.WriteLine("Vowels sum = " + sum);

​

    }

}