import std.stdio;
import std.algorithm;
import std.conv;
import std.datetime;
import std.numeric;
import std.math;
import std.string;

string my_readln() { return chomp(readln()); }

void main()
{//try{
	auto tokens = split(my_readln());
	auto D = to!ulong(tokens[0]);

	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");
	stdout.flush();
/*}catch (Throwable e)
	{
		writeln(e.toString());
	}
readln();*/
}