using System;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
using static System.Console;
using static System.Math;

class Program
{
    static void Main(string[] args)
    {
        WriteLine(ReadLineParseIntArray().Select(x => x - 1).Sum());
    }
    static int[] ReadLineParseIntArray() => ReadLine().Split(' ').Select(int.Parse).ToArray();
}