c
c  Wait to receive a result back from any processor;
c  If more rows to do, send the next one back to that processor.
c
        do i = 1, rows

          call MPI_RECV ( ans, 1, MPI_DOUBLE_PRECISION, 
     &       MPI_ANY_SOURCE, MPI_ANY_TAG, 
     &       MPI_COMM_WORLD, status, ierr )

          sender = status(MPI_SOURCE)    
          anstype = status(MPI_TAG)
          b(anstype) = ans

          if ( numsent .lt. rows ) then

            numsent = numsent + 1

            do j = 1, cols
              buffer(j) = a(numsent,j)
            end do

            call MPI_SEND ( buffer, cols, MPI_DOUBLE_PRECISION, 
     &        sender, numsent, MPI_COMM_WORLD, ierr )

          else

            call MPI_SEND ( MPI_BOTTOM, 0, MPI_DOUBLE_PRECISION, 
     &       sender, 0, MPI_COMM_WORLD, ierr )

          end if

        end do