function Picker(input) {
  var lines = input.split('\n');
  var fields = lines.reduce(function(all, line) { return all.concat(line.split(' ')); }, []);
  var p = 0;

  return {
    int: function() {
      return parseInt(fields[p++], 10);
    },
    float: function() {
      return parseFloat(fields[p++]);
    },
    str: function() {
      return fields[p++];
    }
  };
}

function Main(input) {
  var pick = Picker(input);
  var l = [pick.int(), pick.int(), pick.int(), pick.int(), pick.int()].sort(function(a, b){ return a - b;});
  var k = pick.int();
  
  var min = l[0];
  var max = l[l.length - 1];

	console.log(max - min <= k ? 'Yay!' : ':(');
}

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