What "is worng"? What happens? Code does not compile? Program crashes? Unexpected output?
(We can actually guess some of those answers, but it is better for you if you do explain it.)
Math trivia: (f*2)*(c*2) == f*2*c*2 == f*c*2*2 == f*c*4
Lets look at the first value, matrix[0][0]. The f==0 and c==0, therefore 0*0*4 -> 0.
Same goes for the entire row, for f==0 for all of them and on the first colum the c==0 makes 0.