function Main(input){
    var D = input;
    D = parseInt(D,10);

    switch(D){
        case 25:
            console.log('Christmas');
        break;
        case 24:
            console.log('Christmas Eve');
        break;
        case 23:
            console.log('Christmas Eve Eve');
        break;
        case 22:
            console.log('Christmas Eve Eve Eve');
        break;
    }


}
Main(require('fs').readFileSync('/dev/stdin','utf8'));