using System; using System.IO; using System.Linq; using System.Collections.Generic; class Program { static void Solve() { var a = sc.Int(); var c = sc.Int(); pr.WriteLine(a ^ c); } static void Main(string[] args) { // pr.AutoFlush = true; Solve(); pr.Flush(); } static Scanner sc = new Scanner(); static Printer pr = new Printer(); } #region IO class Scanner { private int _i = 0; private string[] line = new string[0]; private T[] Enumerate(int n, Func f) { T[] ret = new T[n]; for (int i = 0; i < n; i++) ret[i] = f(); return ret; } public string Str() { if (line.Length <= _i) { line = Console.ReadLine().Split(' '); _i = 0; } return line[_i++]; } public int Int() => int.Parse(Str()); public long Long() => long.Parse(Str()); public double Double() => double.Parse(Str()); public int[] Int(int n) => Enumerate(n, Int); public long[] Long(int n) => Enumerate(n, Long); public double[] Double(int n) => Enumerate(n, Double); public string[] Str(int n) => Enumerate(n, Str); } class Printer : StreamWriter { public Printer() : base(Console.OpenStandardOutput()) { AutoFlush = false; } } #endregion