!
      PROGRAM P52
!
!
!     Nested loops to access arrays
!
      IMPLICIT NONE
      INTEGER :: I,J,K,UNITS(12),NQ
      REAL :: SALES(12),SQ
!
!
      PRINT *, 'This is Program >> P52  - Nested loops for arrays'
!
!     Tell program where data for  READ *  is coming from
      OPEN(UNIT=5, FILE='P52.DAT')      ! UNIT=5 is the default input
!
!
L1:   DO I=1,12
         READ 15,UNITS(I),SALES(I)
      END DO L1
   15 FORMAT(I3,F5.1)
      I=0
L2:   DO J=1,4        ! Four quarters
         NQ=0
         SQ=0
L3:      DO K=1,3     ! Each with three months
           I=I+1      ! Month pointer I goes from 1 to 12
           NQ=NQ+UNITS(I)
           SQ=SQ+SALES(I)
         END DO L3
         PRINT 25,J,NQ,SQ
   25    FORMAT(' QUARTER',I2, &  
         I7,' CARS    $',F5.1,' M')
      END DO L2
      STOP
      END PROGRAM P52