improved waste management

encoding works like the first solution

d2 += b4
d2 += b5
d2 += b5
d1 += b3

if b2 {
  d1 += 4
  if b1 {
    flip(d1, d2)
  }
} else {
  d1 += b3
  d1 += b1
}

===== 'NEW SOLUTION 1' =====
 0.	salt-salt-salt-salt-salt	 => 	Lead-Lead
 1.	salt-salt-salt-salt-FIRE	 => 	Tin-Lead
 2.	salt-salt-salt-FIRE-salt	 => 	Silver-Lead
 3.	salt-salt-salt-FIRE-FIRE	 => 	Lead-Silver
 4.	salt-salt-FIRE-salt-salt	 => 	Iron-Lead
 5.	salt-salt-FIRE-salt-FIRE	 => 	Copper-Lead
 6.	salt-salt-FIRE-FIRE-salt	 => 	Gold-Lead
 7.	salt-salt-FIRE-FIRE-FIRE	 => 	Lead-Gold
 8.	salt-FIRE-salt-salt-salt	 => 	Lead-Tin
 9.	salt-FIRE-salt-salt-FIRE	 => 	Tin-Tin
10.	salt-FIRE-salt-FIRE-salt	 => 	Silver-Tin
11.	salt-FIRE-salt-FIRE-FIRE	 => 	Tin-Silver
12.	salt-FIRE-FIRE-salt-salt	 => 	Iron-Tin
13.	salt-FIRE-FIRE-salt-FIRE	 => 	Copper-Tin
14.	salt-FIRE-FIRE-FIRE-salt	 => 	Gold-Tin
15.	salt-FIRE-FIRE-FIRE-FIRE	 => 	Tin-Gold
16.	FIRE-salt-salt-salt-salt	 => 	Lead-Iron
17.	FIRE-salt-salt-salt-FIRE	 => 	Tin-Iron
18.	FIRE-salt-salt-FIRE-salt	 => 	Silver-Iron
19.	FIRE-salt-salt-FIRE-FIRE	 => 	Iron-Silver
20.	FIRE-salt-FIRE-salt-salt	 => 	Iron-Iron
21.	FIRE-salt-FIRE-salt-FIRE	 => 	Copper-Iron
22.	FIRE-salt-FIRE-FIRE-salt	 => 	Gold-Iron
23.	FIRE-salt-FIRE-FIRE-FIRE	 => 	Iron-Gold
24.	FIRE-FIRE-salt-salt-salt	 => 	Lead-Copper
25.	FIRE-FIRE-salt-salt-FIRE	 => 	Tin-Copper
26.	FIRE-FIRE-salt-FIRE-salt	 => 	Silver-Copper
27.	FIRE-FIRE-salt-FIRE-FIRE	 => 	Copper-Silver
28.	FIRE-FIRE-FIRE-salt-salt	 => 	Iron-Copper
29.	FIRE-FIRE-FIRE-salt-FIRE	 => 	Copper-Copper
30.	FIRE-FIRE-FIRE-FIRE-salt	 => 	Gold-Copper
31.	FIRE-FIRE-FIRE-FIRE-FIRE	 => 	Copper-Gold