Sympy

A grade

{ 2, 3 }

B grade

{ 1, 4, 5, 18 }

C grade

{ }

F normal fail

{ 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 }

F(-1) timedout fail

{ 19, 20, 21 }

F(-2) exception fail

{ }