const input = require('fs').readFileSync('/dev/stdin', 'utf8');

const output;

if(output === '25') {
  output = 'Christmas';
} else if(output === '24') {
  output = 'Christmas Eve';
} else if(output === '23') {
  output = 'Christmas Eve Eve';
} else if(output === '22') {
  output = 'Christmas Eve Eve Eve';
} else {
  output = null;
}

console.log(output);