function Main(input){
  
  var str = input;
  var tmp = str.split("\n");
  var k = tmp[5];
  tmp.pop();
      //console.log(abcde);
  
  var max = Math.max.apply(null, tmp);
  var min = Math.min.apply(null, tmp);
  
  if(max-min>k){
  console.log(":(");
  }else{
    console.log("Yay!");

  }

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