Choosing new tires: can't find my size on schwalbe site
Your bike had these tyres as stock in 2015 Cross 40c Front - Cross 40c Rear according to http://www.tredz.co.uk/.Merida-Crossway-40-2015-Hybrid-Sports-Bike_74298.htm

2014 version was listed as Tyres:  Cross 700 40C

So you have a 700c rim which can take a 40mm wide tyre.

Confirm this by looking at the sidewall of the tyres, it should say 622-40 or 40-622 somewhere on it.   

Any cyclocross tyre should be good up to a width of 40mm, and you might be able to go a little bit larger if the frame and brakes have clearance.

TBH tyre sizing nomenclature is a horrendous mess.  If you want to know more, click here How are tire sizes measured?