const input = require('fs').readFileSync('/dev/stdin', 'utf8');
 
if (Number(input) === 25) {
  console.log('Christmas');
} else if (Number(input) === 24) {
  console.log('Christmas Eve');
} else if (Number(input) === 23) {
  console.log('Christmas Eve Eve');
} else {
  console.log('Christmas Eve Eve Eve');
}