Let
A = \(\left(\begin{array}{lllll} 1 & 1 & 0 & 0 & 1 \\ 1 & 1 & 1 & 1 & 3 \\ 1 & 1 & 4 & 4 & 4 \end{array}\right)\)
and B be a 5 × 5 real matrix such that AB is the zero matrix. Then the maximum possible rank of B is equal to ___________.
Enter numerical value using the virtual keypad. Round off where necessary.