function Main(input){ 
  var D = parseInt(input,10);
  if(D == 25){
  console.log("Christmas");    
  }else if(D == 24){
    console.log("Christmas Eve");
  }else if(D == 23){
    console.log("Christmas Eve Eve");
  }else if(D == 22){
    console.log("Christmas Eve Eve Eve");
  }
}
    Main(require('fs').readFileSync('/dev/stdin','utf8'));