Similarly to HW2, you want to travel from city A to city B, both located on a straight line. The distance between A and B is M > 0. This time, you travel by car, and, to reach city B, you might need to refuel. There is a gas station at the initial location, and in n locations between A and B: you are given array a1, . . . , an, where ai denotes the distance from A to the i-th gas station. Since your car has limited fuel capacity, you can only travel at most distance D 0 between refuels. In addition, the more fuel your car has, the heavier the car is, and hence you will spend more fuel per mile of travel. You tried to do the math, but after few hours you gave up and decided to use the following simplified model: if after refuel you travel distance (before the next refuel or before reaching B), then you pay 2 b c, where b 0 and c 0 are given to you. Find the minimum cost for the trip from A to B. Please do the following: Formulate the sub