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