int fine=0;

            if(returned_y<due_y){
                fine = 0; 
            } else if(returned_y>due_y){
                fine = 10000;
            } else if(returned_m>due_m){
                    fine = (returned_m-due_m)*500;
            } else if(returned_d>due_d){
                    fine = (returned_d-due_d)*15;
            }
        System.out.println(fine);