Imagine if the country where you lived changed its name.
That is exactly what's happened for the people of Macedonia - it's started using a new name.
The country in south east Europe held a vote last year on changing it to the Republic of North Macedonia.
So, why would a country change its name?
It's to avoid confusion with its southern neighbour Greece which has its own region also called Macedonia.
It's hoped the name change will end a 27-year dispute between the two countries, though some people in both countries are angry about the idea.
Nato stands for the North Atlantic Treaty Organisation and is an international organisation which brings together the armies of various countries, including Britain and the United States.
It's not the first country to change its name. How many others do you know?
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