Updated production rules:
rule_2: A2 -> 24 22 23 A7 A6
rule_6: A6 -> 15 2 14 1
rule_21: A19 -> 20 26 31 25
rule_28: A24 -> A3 A25 25
rule_34: A27 -> A8 A30 23
rule_41: A33 -> 9 36 37 35
rule_46: A37 -> 1 A13 A38
rule_48: A38 -> 6 4 39 3