I inserted the minimal terminals so that each non‐terminal used in the derivation can match its piece of the target.  In rule_1 I add the 22 after A26; in rule_53 I add a 7 at the end of the A19→8 A20 production; in rule_42 I add a 7 so that A14→9 produces two tokens; and in rule_63 I add an 8 so that A22→6 A20 7 yields the needed “6 8 3 7” piece.

Updated production rules:
rule_1: A1 -> A3 A25 21 A26 22 A3 A25 18 A24 A3 16 A2 A18
rule_42: A14 -> 9 7
rule_53: A19 -> 8 A20 7
rule_63: A22 -> 6 8 A20 7