import std.stdio, std.string, std.conv;
import std.typecons;
import std.algorithm, std.array, std.range, std.container;
 
void main() {
	auto D = readln.split[0].to!int;
	auto c =
		D == 25 ? "Christmas" :
		D == 24 ? "Christmas Eve" :
		D == 23 ? "Christmas Eve Eve" :
		D == 22 ? "Christmas Eve Eve Eve" : "";
	c.writeln;
}
