http://ideone.com/cfqTA0 Could anyone help me to fix this error. java.lang.NullPointerException at Main.Solve(Main.java:18) at Main.Run(Main.java:57) at Main.main(Main.java:12) I dont know why this code have this errors. It running normal and give correct answer on my computer, but when i submited on timus, it is non zero error. This problems in acm.timus.ru is 1297. Sorry for my bad english. Anyway, thanks you for reading.