using System;

namespace _05_AddSubstract
{
    class Program
    {
        static void Main(string[] args)
        {
            int firstNumber = int.Parse(Console.ReadLine());
            int secondNumber = int.Parse(Console.ReadLine());
            int thirdNumber = int.Parse(Console.ReadLine());

            int result = Add(firstNumber, secondNumber);
            int finalResult = Substract(result, thirdNumber);

            Console.WriteLine(finalResult);

        }

        public static int Add(int firstNumber, int secondNumber)
        {
            int result = firstNumber + secondNumber;
            return result;
        }

        public static int Substract(int result, int thirdNumber)
        {
            int finalResult = result - thirdNumber;
            return finalResult;
        }
    }
}