function main(arg) {
	arg = Number(arg.split("\n")[0])
	if (arg === 25) console.log('Christmas')
	else if (arg === 24) console.log('Christmas Eve')
	else if (arg === 23) console.log('Christmas Eve Eve')
	else if (arg === 22) console.log('Christmas Eve Eve Eve')
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));