'use strict';

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', function(inputStdin) {
    inputString += inputStdin;
});

process.stdin.on('end', function() {
    inputString = inputString.split('\n');
    main();
});

function readline() {
    return inputString[currentLine++];
}

// main funtion .. code start ..... ///
function main() {

//var input = readline()
var t = Number(readline())
    if(t == 25) console.log('Christmas')
    else if(t == 24) console.log('Christmas Eve')
    else if(t == 23) console.log('Christmas Eve Eve')
    else console.log('Christmas Eve Eve Eve') 
}