Build failed notification

[J0E45]

I'm learning and I'm trying to make a simple program using the Java language. there is an error in my program and the result, a notification appears like this.

my mistake was that reflexively I immediately pressed the proceed button and the result is like this every time I make a division program with the result of a fractional number.

division by the result of a fractional number always results in an integer if the number is not stored in the first variable in the calculation operation.
Is there any solution to this?