How many countries have exclaves? Or, if it's easier, how many countries allow exclaves within their borders?

An exclave is a region of a country that is separated from the rest of the country by another nation. So for example, Alaska is an exclave because to get to the rest of the US by land a person would have to travel through Canada. There are well over 100 exclaves in the world.

The most interesting exclaves belong to Belgium with 22 that are within the Netherlands!

The true champion of exclavery has to be Baarle-Hertog, which is part of Belgium but has a series of tiny exclaves surrounded by the Netherlands. There are 22 in total, and these are made even more insanely complicated by the fact the Netherlands commune of Baarle-Nassau has seven exclaves within Baarle-Hertog. In several instances, the border runs through people's houses.

The country that looks like it has the most is Russia with 55! Most are tiny.

https://en.wikipedia.org/wiki/List_of_enclaves_and_exclaves

Another interesting case was Dahala Khagrabari, the world's only third-degree-exclave. It was a piece of India within a piece of Bangladesh within a piece of India within Bangladesh until it was finally ceded to Bangladesh in 2015.

https://en.wikipedia.org/wiki/Dahala_Khagrabari