I also came up with 9.... but the compiler statement made me wonder if I could find a language that answers with 1:

Python: 9
Go: 9
c14=9
C11=9
C++98 = 9
php=9
Cobol=9 (that was a pain!!)
erlang=9
TCL=9
Scala=9
Rust=9
Pike=9
NIM=9
Julia=9
Fortran=9

Nope couldn't find one!