There isn't one.
There are three countries in Europe that start and end with A. The three countries are Albania, Andorra and Austria.
Afghanistan and Azerbaijan are countries. They begin with the letter A and end with a letter other than A.
Azerbaijan and Afghanistan are two countries that start with an A but don't end with an A.
There are zero countries that end in the letter 'w'. Interestingly enough, there are also no countries that start with a 'w'.
There are 11 countries that start with the letter "A" but do not end with "A." These countries are Afghanistan, Azerbaijan, and Antigua and Barbuda. The rest either end with "A" or are not included in the count.
There are two countries that start with the letter "A" but do not end with it: Afghanistan and Azerbaijan.
There are two countries that start with the letter "A" and end with the letter "N": Azerbaijan and Afghanistan.
Nine of them.
The European Union is still in existence and working reasonably well for most of the countries involved.
There are no countries that begin and end with the letter n.
There are only two countries I know which start and end with those letters, and they are: Barbados Bahamas
Tuvalu