<|im_start|>user
How many countries in Europe do have the Euro as monetary currency?

Context:
The euro area, commonly called eurozone (EZ), is a currency union of 20 member states of the European Union (EU) that have adopted the euro (€) as their primary currency and sole legal tender, and have thus fully implemented EMU policies.<|im_end|>
<|im_start|>assistant
20<|im_end|>
