Tell me an interesting fact about Bulgaria.
Bulgaria is the only country in Europe that has not changed its name since it was first established. The country and its people have been called Bulgaria since the 7th century.
Complete the following task based on the instruction and optional input provided.### Instruction:
Tell me an interesting fact about Bulgaria.

### Output:
Bulgaria is the only country in Europe that has not changed its name since it was first established. The country and its people have been called Bulgaria since the 7th century.