Please show me the pictures and steps in details.

For each of the following languages over the alphabet sigma = {a, b}, give a DFA that recognizes the language. L_1 = {lambda, b, ab} L_2 = {w sigma^*|w begins with and "a" and ends with a "b"}. For any string w sigma^*, let n_a(w) denote the number of a's in w. For example n_a(abbbba) = 2. Define the language L_3 = {w sigma^* |n_a(w) mod 3 = 1}. L_4 = L_3 where L_3 is the language in part c)