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'));