'use strict';

function Main(input) {
  var N = Number(input.split("\n")[0]);
  if(N == 1) {
    console.log("Hello world");
  }
  if(N == 2) {
    var A = Number(input.split("\n")[1]);
    var B = Number(input.split("\n")[2]);
    console.log(A + B);
  }

};

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