Calculating residential time for citizenship

[sky2]

I lived in Finland on B-permit on irregular intervals (ie. lived for one year, moved away for an year, and then returned back and went back again). The total irregular period of stay in Finland is 2 years. However I have been living in Finland continuous 4 years on A-permit.

So, how should I calculate the residence permit time? Should I put 5 years ? (1 year which is half of total 2 years residence under B permit + 4 years of continuous A permit). I am thinking to put 4 years only, which is the time since I got A residence permit.

Muutin Suomeen asumaan?
Date when I got A residence permit

Olen asunut Suomessa yhteensä:
4 years (since I got A-permit)

Is it OK?

I am not sure about above questions because basically I moved to Finland long ago very first time but left shortly after that. So should I put the date when I got the residence permit A?

Thanks.

[caster]

Four years - is the requirement - you can always explain while attaching a note.

No matter what you write - at time of document verification you have the possibility to explain and they can amend whatever they think is right as they have all the information with them.