function Main(input) {
  input = input.split("\n");
  n = parseInt(input[0], 10);

  if(n == 25) {
    console.log("Christmas")
  } else if(n == 24) {
    console.log("Christmas Eve");
  } else if(n == 23) {
    console.log("Christmas Eve Eve");
  } else if(n == 22) {
    console.log("Christmas Eve Eve Eve");
  }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));