C     ITERATIVE FORTRAN SOURCE CODE
C
      INTEGER I,  J
      REAL    A0, B0, C0, D0
      REAL    A1, B1, C1, D1
C
      DATA A0/1.0/, B0/2.0/, C0/3.0/, D0/4.0/
C
      DO 10 I=1,1000
        DO 10 J=1,1000
          A1 = C0 - B0
          B1 = D0 / B0
          C1 = A0 + B0
          D1 = B0 * B0
          A0 = C1 - B1
          B0 = D1 / B1
          C0 = A1 + B1
          D0 = B1 * B1
   10 CONTINUE
C
      WRITE(*,1000) A1, B1, C1, D1
 1000 FORMAT(4F10.1)
      END
