Complexities of realizations in the number of circuits count

Question

Solve the following problem:

Draw the state diagram and the state transition table for a two-bit counter with two control inputs k₁, k₂ defined as follows

If k₁k₂ = 00, stop counting,

If k₁k₂ = 01, count up by 1,

If k₁k₂ = 10, count down by 1,

If k₁k₂ = 11, count by two.

Implement the counter by T, D, and JK-flip-lops and compare the complexities of realizations in the number of circuits count. Available are two-input circuits.