"use strict";
// import bigInt from 'big-integer'

const Main = input => {
  const wrongAnswers = input.trim().split("\n");
  const answer = ["1", "2", "3"].filter(num => !wrongAnswers.some(wa => wa === num));
  console.log(answer);
};

Main(require("fs").readFileSync("/dev/stdin", "utf8"));
