Marinada '15

%V0 $$f(10) = 5$$ $$f(8) = 4$$ $$f(16) = 8$$ $$f(3) = 3$$ $$f(2) = 3$$ $$f(1) = 5$$ $$f(100) = 3$$ $$f(103) = 6$$ $$f(102) = 6$$ $$f(101) = 8$$ $$f(7) \cdot f(4) = ?$$