how to count duplicate values in datagridview c# forms

Question

hai friends ,


 please help me to count duplicate values from datagridview in c# windows forms...

 HERE I NEED TO COUNT TOTAL NUMBER OF P's IN A ROW AS SHOWN BELOW

s.no	name	Jan-01	Jan-02	Jan-03	Jan-04	Jan-05	TOTAL PRESENT
1	chiru	p	p	A	P	P	4
2	venu	P	P	P	A	P	4
3	naveen	P	P	A	P	A	3
4	tanu	P	A	P	P	P	4
5	tanushree	A	P	A	P	P	3
6	vandu	A	P	A	P	A	2

 THANKS IN ADVANCE