how can I SUM a variable number of cells from 1 to 52?

Hello, I need some help. I have to sum up to 52 week in one cell if on if the cell are identical then bring N/A. I was trying with the conditional if, but it stop in the condtion week 24. here a example that I did:

IF ($C$1=$K1, K2, IF($C$1=$L1, SUM(K2:L2, IF($C$1=$M$1,SUM(K2:M2………. And so on, just to IF ($C1=$BW1, SUM(K2:BW2).

Please I have to solve this problem as soon as posible. I will acept all recomenation.

Regards