var Main = function(Input){
  if(Input == '25'){
    console.log('Christmas');
    return;
  } else if(Input == '24'){
    console.log('Christmas Eve');
    return;
  } else if(Input == '23'){
    console.log('Christmas Eve Eve');
    return;
  } else if(Input == '22'){
    console.log('Christmas Eve Eve Eve');
    return;
  }
}
Main(require('fs').readFileSync('/dev/stdin', 'utf8'));