Long seed = Long.parseLong(args[1]);
try {
System.out.println("loading save: "+fn);
DataInputStream in = new DataInputStream(new GZIPInputStream(new FileInputStream(fn)));
AnyTag tag = NamedTag.read(in);
LongTag seedTag = (LongTag) tag.unpack().get("Data").get("RandomSeed");
seedTag.setData(seed);
DataOutputStream out = new DataOutputStream(new GZIPOutputStream(new FileOutputStream(args[2])));
tag.write(out);
out.close();
System.out.println("done");