Fortran bug?

[Bill Lasher]

I believe you are violating the rule that says you can't go to a statement
within a DO loop except from the top.  I tried the program on our mainframe
(IBM) using two different compilers.  The IBM FORTRAN 77 compiler accepted
the statements, but the WATFIV compiler did not.

I'm not sure what the standard reads, but I recommend separating the loops.
That way there is no question.