The problem is with the encoding of the input file. Use the other constructor for Scanner
that specifies a character set:
Scanner first_line = new Scanner(file, "UTF-8");
Using other constructors results in the default character set being used which typically cannot correctly read unicode characters.
Workaround:
BufferedReader br = new BufferedReader(new FileReader("book1_enc.dat"));
int sizeSt = Integer.parseInt(br.readLine());