RCM LIABILITY PAID IN GSTR1 IN AUG 17 RETURN, BUT ITC NOT CLAIMED. WHAT REMEDY

RCM liability paid in August 2017 but ITC not claimed in August 17 GSTR3B - will some one please help me offering clarification how to deal with this while preparing Anuual Return 9 of 2017 18. Will I get input credit though not claimed  in 3B