Let X = {0, 1, 2} and Y = {0,1,2,3}. Now we define f={(0,1),(1,2).(2,1)] Please enter your answer as a sum of the following numbers (they are not mutually exclusive): . 1ifff is a function f : X Y 2iff fis a function and it is also injective 4iff fis a function and it is also surjective This means that your answer can be 0 (not a function), 1 (a function but neither injective or surjective 3 (a function that is only injective but not surjective).5 (a function that is only surjective but not injective) or 7 (a function that is bijective)