for a:=0 to maxa do
for b:=0 to maxb do
for c:=0 to maxc do
for d:=0 to maxd do
begin
for i:=0 to a do
for j:=0 to b do
for k:=0 to c do
for l:=0 to d do
if things[a,b,c,d]>things[i,j,k,l]+things[a-i,b-j,c-k,d-l] then
things[a,b,c,d]:=things[i,j,k,l]+things[a-i,b-j,c-k,d-l];
end;