Analyze the complexity of algorithm A1 where the problem of size n is solved by dividing into 4 subprograms of size n-4 to be recursively solved and then combining the solutions of the subprograms takesO(n2) time. Determine the recurrence and whether it is Subtract and Conquer or Divide and Conquertype of problem. Solve the problem to the big O notation. Use the master theorem to solve, state which theorem you are using and whyand show step-by-step work. In the answer you must explain how you obtained the recurrence from the problem description and show how you solved step by step using one of the master theorems.