I have 2 tickers both ending with s as per below

ITU3 BS
AXSB IS

I need to change the first ticker to end with Z and the 2nd ticker to end with N. I need to use only one formula to do so. What I mean is that if I put that same formula in cells A1 and A2 while the tickers will be in B1 and B2, the results will be ITU3 BZ and AXSB IN in A1 and A2.

Thanks!