Check duplicate

Hello,
I have 2 file (input , report)

I want to check dup condition as below.

Check Dup
1.1 Check dup column SR# in file input or not If dup stamp Y in column Check Dup

1.2 Check dup with file report if match column SR and column Activity check column Closed Date file report have text or not
1.2.1 If text = ?working? or blank ----> stamp N in column Check Dup

1.3 Check dup with file report if match column SR → check column Closed Date file report have text or not
1.3.1 If text = ?working? or blank ----> stamp Y in column Check Dup
1.3.2 If text <> ?working? but have value ----> stamp N in column Check Dup

Please guide me for solve it (vba , formular)
Thank you.

Hello,
I have 2 file (input , report)

I want to write formular in file input as below.


1. check column C (file input) that dup with prevoius row or not ----> IF(COUNTIF(C$2:C2,C2)=1 stamp N ---> else check step2
2. check column C (file input) with column C (file report) and check column M (file input) with column D (file report) ---->. If not match check step3 , If match check step 4
3. check column C file input with column C (file report) ----> If found not match stamp N ---> else check step 4
4. check column I (file report) that have text "working" or blank ---> If match stamp N ----> else stamp Y

remark :
- output I want stamp in file input column O (check dup).
- file report I want to check from bottom to top.

Please guide me for solve it. (formular)

Thank you