function Main(input) {
  input = input.split("\n");
  var a = ~~input[0];
  var b = ~~input[1];
  var c = ~~input[2];
  var d = ~~input[3];
  var e = ~~input[4];
  var k = ~~input[5];

  var AtCoder = function(a,b,c,d,e,k){
    this.antena = [a,b,c,d,e];
    this.distance = k;
  };

  AtCoder.prototype = {
    procedure: function(){
      for(var antena1 of this.antena){
        for(var antena2 of this.antena){
          if(Math.abs(antena1-antena2) > this.distance) return false;
        }
      }
      return true;
    }
  }

  var atcoder = new AtCoder(a,b,c,d,e,k);
  if(atcoder.procedure() == true){
    console.log("Yay!");
  }else{
    console.log(":(");
  }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
