function main(input) {
    switch(input) {
      case "25":
        console.log("Christmas");
        break;
      case "24":
        console.log("Christmas Eve");
        break;
      case "23":
        console.log("Christmas Eve Eve");
        break;
      case "22":
        console.log("Christmas Eve Eve Eve");
        break;
    }

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));