Hi everyone. I'm solving problem in Usaco 5.1.4 "Musical Themes", but i get runtime error on test 9. It says: "Bad syscall #32000175 (RT_SIGPROCMASK).Your program printed data to stderr. terminate_called_after_throwing_an_instance_of_'St9bad_alloc'__what():__std::bad_alloc."

Test 9: SIGNAL 50 (0.521 secs, 16340 KB)

What does signal 50 means????