Why does the code print negative numbers?

Question

That is a fibonacci generator. On ~45 number prints negative. why?
https://code.sololearn.com/cf2czO30H8JV/?ref=app

Answer 1

The int datatype has a maximum value of (2 ^ 31) - 1 minimum value of -(2 ^ 31) , when your number reaches that it will drop to -(2 ^ 31) and start counting from there
If my explanation confuses you let me explain with byte
Byte can store numbers in the range -128 to 127
so this: byte x = 130 is effectively -126

Answer 2

Using long will work better