Cоnsider the relаtiоnаl schemа R(A, B, C, D, E, F) with the set S = {A → C, CD → E, F → A, CE → D} оf functional dependencies. Find all candidate keys of R by using the tableau (7‐step) method. [Symbols: →, ∪, ∩, ⊆, ⊂, ∈, ∉, ∅, −]