7 A 6 P & R $ 4 Y Q % T @ 3 9 S I O 9 9 J L E U * K # 3
STEP I- The letters which are immediately preceded and immediately followed by a symbol are arranged in the end of the series in the alphabetical order. (They are arranged just after 3)
STEP II- The numbers which are immediately preceded by the letter and immediately followed by the Symbol are arranged between 9 and S in the increasing order.
STEP III- The numbers which are immediately followed by letter are interchanged its position with respect to the element just after it. (STEP II is applied after STEP I and STEP III is applied after STEP II)