function Main(input) {
  input = input.split('\n');
  var limit = input[input.length -1];
  var max = input[input.length-2];
  var min = input[0];
  var maxDistance = max - min;
  if(maxDistance > limit) {
    console.log(':(');
  } else {
    console.log('Yay!');
  }
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));
