function Main(input){
 const lines = input.split('\n');
  if (lines[0] === 1){
  return 'HELLO WORLD'
  }
  if (lines[0] === 2){
  return (lines[1]*1) + (lines[2]*1)
  }
}
console.log(Main(require("fs").readFileSync("/dev/stdin", "utf8")));