4. Number of elements in the intersections of sets

If \(n(A \cup B \cup C) = 63\), \(n(A) = 35\), \(n(B) = 32\), \(n(C) = 31\), \(n(A \cap B) = 22\), \(n(B \cap C) = 18\), and \(n(A \cap C) = 12\), then find out \(n(A \cap B \cap C)\).

 

\(n(A \cap B \cap C)\) \(=\)