A sequential circuit contains a register of four flip-flops. Initially, a binary number N (0000 ≤ N ≤ 1100) is stored in the flip-flops. After a single clock pulse is applied to the circuit, the register should contain N + 0011. In other words, the function of the sequential circuit is to add 3 to the contents of a 4-bit register. Design the circuit using J-K flip-flops.