A 4x4 grid shows integer costs in each cell. The top-left cell is green (start) and the bottom-right cell is red (goal). A yellow Pac-Man starts on the green cell. Animate Pac-Man moving step-by-step along a path from start to goal that maximizes the sum of costs collected (each time Pac-Man enters a cell, add that cell's cost). Only orthogonal moves (up/down/left/right). Keep the grid lines and cell cost numbers unchanged; only Pac-Man should move. Only modify what the task requires; keep the background and any other element unchanged.