Formula to value unique characters only

I need a formula that will recognize duplicates and only show a "1" for just one of the duplicates and nothing for the others. For example, if column A looks like:

aaa
bbb
bbb
bbb
ccc
ccc

Then column B should look like:

1
1
0
0
1
0

Basically adding a "1" to any unique number, then a "0" for the following duplicates. Any help would be greatly appreciated.

Enter B1

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then pull down

Perfect! thank you!