#include <incmode>.

#const istop = "SAT".

#const imin = 1.

#const imax = 50.

#const maxgrid = 4.

#program base.

loc(lower_right_ladder).

loc(lower_left_ladder).

loc(key).

loc(right_door).

loc(plat1).

loc(devilleft).

at(plat1,1).

cost(0,1).

cost(0,0).

#program step(k).

{move(L,k)} :- loc(L), at(L1,k),L1!=L.

at(L,k) :- at(L1,k-1),move(L,k-1).

cost(C+50,k) :- move(L,k-1), at(L1,k-1), #count{Z:ro(at(L1),move(L),Z)}=0, not picked(key,k-1), cost(C,k-1).

cost(C+50,k) :- move(L,k-1), at(L1,k-1), #count{Z:ro((at(L1),picked(key)),move(L),Z)}=0, picked(key,k-1), cost(C,k-1).

cost(C+Z,k) :- move(L,k-1), at(L1,k-1), not picked(key,k-1), ro(at(L1),move(L),Z), cost(C,k-1).

cost(C+Z,k) :- move(L,k-1), at(L1,k-1), picked(key,k-1), ro((at(L1),picked(key)),move(L),Z), cost(C,k-1).

picked(key,k) :- at(key,k).

:- picked(key,k),at(right_door,k),move(L,k).

:- at(lower_right_ladder,k),picked(key,k), move(devilleft,k).

:- at(devilleft,k),move(plat1,k).

:- at(plat1,k), not picked(key,k), move(right_door,k).

{at(L,k)} :- at(L,k-1).

cost(Q,k) :- cost(Q,k-1), not move(L,k-1):loc(L).

picked(key,k) :- picked(key,k-1).

:- #count{Q:cost(Q,k)}!=1.

:- #count{L:at(L,k)}!=1.