Update build-systems.md
Add missing space
Closes #15104.
PiperOrigin-RevId: 436804683
diff --git a/site/en/basics/build-systems.md b/site/en/basics/build-systems.md
index d4683e1..1e4185a 100644
--- a/site/en/basics/build-systems.md
+++ b/site/en/basics/build-systems.md
@@ -34,7 +34,7 @@
directory and turn it into a binary class file. In the simplest case, this is
all you need.
-However, as soon as code expands,the complications begin. `javac` is smart
+However, as soon as code expands, the complications begin. `javac` is smart
enough to look in subdirectories of the current directory to find code to
import. But it has no way of finding code stored in _other parts_ of the
filesystem (perhaps a library shared by several projects). It also only knows
