COUNT across multiple columns with single column criteria

Hi

I'd like to count the number of times a specific entry appears across multiple columns using single column criteria.

eg.

Col1...Col2...Col3...Col4...Col5
yes......a........b
no........a.......b........c........d
yes.......a.......b........c........d

Let's say I want to count the number of time "a" appears but only when "yes" is in column 1. Normally I use COUNTIFS, but just found out that won't work unless both ranges are the same size. I could use multiple COUNTIFS, one for every column, but that becomes impractical as my columns grow in number. Is the only answer an array formula and if so could someone show me the correct syntax?

many thanks

Brilliant, Thanks, Ali.