function Set(A){this.map=new Map(A)
}Set.placeholder=new Object();
Set.prototype.size=function(){return this.map.size()
};
Set.prototype.isEmpty=function(){return this.map.isEmpty()
};
Set.prototype.clear=function(){return this.map.clear()
};
Set.prototype.add=function(A){return(this.map.put(A,Set.placeholder)==null)
};
Set.prototype.contains=function(A){return this.map.containsKey(A)
};
Set.prototype.remove=function(A){return(this.map.remove(A)==Set.placeholder)
};
Set.prototype.values=function(){return this.map.keys()
};
Set.prototype.toString=function(){return"[object Set]"
};