Anjali and her fat cat

Anjali's cat is getting fat day by day so she needs to consult a vet doctor but she is on a low budget so needs take every step carefully. Initially, she is at the position 0,0 with $A$ units in her hand. The vet is at the position $M,N$. She needs to travel to that point in the shortest path possible as every step cost her $P$ units. The vet charges $D$ units per visit. Your task is to tell Anja