Remove duplicates of number

[Money]

Hi all

I'm tring to remove duplicates from the column.

column presents numbers, - , and Taken. 

I need to remove only number duplicates and needs to keep "-" and "Taken" as it is. 

Sharing below the current data and expected data.

current data	expected data
1	1
1	2
2	3
3	4
-	-
4	taken
taken	taken
taken	5
5	6
3	-
6	7
-
7

Please suggest me how to approach. 

Thanks in advance 🙂 

@tamerj1  @amitchandak @Greg_Deckler @Arul @v-zhangti @PowerQuerryGuru @Ashish_Mathur @FreemanZ

[AlexisOlson]

You can do a Group By where you make sure "taken" and "-" are treated uniquely.

Here's a sample query you can paste into the Advanced Editor in a new blank query:

let
    Source = Table.FromColumns({{"1", "1", "2", "3", "-", "4", "taken", "taken", "5", "3", "6", "-", "7"}}, {"current data"}),
    #"Added Index" = Table.AddIndexColumn(Source, "Index", 1, 1, Int64.Type),
    #"Added Custom" = Table.AddColumn(#"Added Index", "Custom", each if [current data] = "taken" or [current data] = "-" then [Index] else 0, Int64.Type),
    #"Grouped Rows" = Table.Group(#"Added Custom", {"current data", "Custom"}, {}),
    #"Removed Other Columns" = Table.SelectColumns(#"Grouped Rows",{"current data"})
in
    #"Removed Other Columns"

 This creates a unique index but then zeros it out for the numbers so that they aren't treated uniquely.