Design a two$-$bits counter with inputs $"$up$"$ and "down" $($in addition to the common clock$)$ using two JK flip$-$flops. A third SR flip$-$flops stores whether or not the counter should currently be counting $"$up$"$ or "down"; the $"$up$"$ input makes the clock start counting $"$up$"$ and the "down" input makes the clock start counting "down".