function main(input) {
  var a = input[0]-0;
  var ans = "";
  switch(a){
    case 25:
      ans = "Christmas";
      break;
    case 24:
      ans = "Christmas Eve";
      break;
    case 23:
      ans = "Christmas Eve Eve";
      break;
    case 22:
      ans = "Christmas Eve Eve Eve";
      break;
  }
  console.log(ans);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8').trim().split("\n"))
