import std.stdio, std.math, std.algorithm, std.array, std.string, std.conv, std.container, std.range;
T Read(T)() { return readln.chomp.to!(T); }
T[] Reads(T)() { return readln.split.to!(T[]); }
alias read = Read!(int);
alias reads = Reads!(int);


void main() {
    int d = read();
    if (d == 25)
        writeln("Christmas");
    else if (d == 24)
        writeln("Christmas Eve");
    else if (d == 23)
        writeln("Christmas Eve Eve");
    else if (d == 22)
        writeln("Christmas Eve Eve Eve");
}