Sample - Student Attendance

	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P
1									From: https://stackoverflow.com/questions/61704982/google-sheets-calculate-characters-only-once?noredirect=1#comment109151140_61704982
2
3	Student Name	Mon	Tue	Wed	Thu	Fri	Mon	Tue	Wed	Thu	Fri	Mon	Tue	Wed	Thu	Fri
4	John1				y					uyurturt		y	y	x	x	x
5	John2				x							o	o	x	x	x
6	John3				o							x	x	x	x	x
7	John4				x			vcz				x	x	y	y
8	John5				x										o
9	John6				y										x
10	John7				o				utr						x
11	John8
12	John9				x
13	John10				y
34		9					3					8
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