List<Student> st = new ArrayList<Student>();
Scanner sc = new Scanner(System.in);
sc.useDelimiter("-");
for(int i = 0; i < 10; i++){
int id = sc.nextInt();
int score = sc.nextInt();
st.add(new Student(id, score));
}

1011-40
1002-50
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:909)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at SortScore.main(SortScore.java:20)