As stated, in dynamic programming we first solve the subproblems and then choose which of them to use in an optimal solution to the problem. Professor Capulet claims that we do not always need to solve all the subproblems in order to find an optimal solution. She suggests that we can find an optimal solution to the matrix chain multiplication problem by always choosing the matrix A_k at which to split the subproduct A_iA_{i + 1} . . . A_j (by selecting k to minimize the quantity p_{i - 1}p_kp_j) before solving the subproblems. Find an instance of the matrix-chain multiplication problem for which this greedy approach yields a suboptimal solution.