function main(input) {
  const D = parseInt(input, 10);
  if(D==25){
    console.log("Christmas");
  }else if(D==24){
    console.log("Christmas Eve");
  }else if(D==23){
    console.log("Christmas Eve Eve");
  }else if(D==22){
    console.log("Christmas Eve Eve Eve");
  }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));