function Main(input) {
  input = input.trim()
  input = input.split("\n").map(Number);
  var N = input[5];
  input.pop();
  function compareFunc(a, b) {
  return a - b;
}
  input.sort(compareFunc);
  if(input[4]-input[0]<=N) console.log("Yay!");
  else console.log(":(")
}Main(require("fs").readFileSync("/dev/stdin", "utf8"));
