using System;

public class Program

{

    public static void Main()

    {

        int i,j,fn,sn,res=0;

        Console.WriteLine("Enter First number (less):");

        fn = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("Enter First number (more):");

        sn = Convert.ToInt32(Console.ReadLine());

        for(i=fn;i<=sn;i++)

        {

            j = i%2;

            if(j==0)

            {

                continue;

            }

            res +=i;

        }

        Console.Write("{0}",res);

    }

}