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

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