AoC 2019 Day7 FORTRAN (for day9 intcode)

PROGRAM DAY7
  USE MPI

  INTEGER :: I,N,IERR
  INTEGER(8) :: A,B,C,D,E,PART1,PART2,RES,INIT
  CHARACTER(LEN=1) CHAR
  INTEGER, ALLOCATABLE :: PROG(:)
  INTEGER :: IERROR, NPROC, ICOMM, IRANK, INTERCOMM,ERRCODES(5)
  LOGICAL :: AMROOT
  INTEGER :: STATUS(MPI_STATUS_SIZE)

  CALL MPI_INIT(IERROR)
  ICOMM = MPI_COMM_WORLD
  CALL MPI_COMM_SIZE(ICOMM,NPROC,IERROR)
  CALL MPI_COMM_RANK(ICOMM, IRANK, IERROR)
  CALL MPI_COMM_SPAWN("./intcode",MPI_ARGV_NULL,5,MPI_INFO_NULL,0,ICOMM,INTERCOMM,ERRCODES,IERROR)

  OPEN(1,FILE="input.txt")
  N=1
  DO
     READ(1,'(A1)',IOSTAT=IERR,ADVANCE="NO")CHAR
     IF(IERR.NE.0)EXIT
     IF(CHAR.EQ.",")N=N+1
  END DO
  REWIND(1)
  ALLOCATE(PROG(0:N-1))
  READ(1,*)PROG
  DO I=0,4
     CALL MPI_SEND(N,1,MPI_INTEGER,I,0,INTERCOMM,IERROR)
     CALL MPI_SEND(PROG,N,MPI_INTEGER,I,1,INTERCOMM,IERROR)
  END DO
  INIT=0
  PART1=0
  DO A=0,4
     DO B=0,4
        IF(B.EQ.A)CYCLE
        DO C=0,4
           IF(ANY((/A,B/).EQ.C))CYCLE
           DO D=0,4
              IF(ANY((/A,B,C/).EQ.D))CYCLE
              DO E=0,4
                 IF(ANY((/A,B,C,D/).EQ.E))CYCLE
                 CALL MPI_SEND(A,1,MPI_DOUBLE_PRECISION,0,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(INIT,1,MPI_DOUBLE_PRECISION,0,3,INTERCOMM,IERROR)
                 CALL MPI_SEND(B,1,MPI_DOUBLE_PRECISION,1,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(C,1,MPI_DOUBLE_PRECISION,2,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(D,1,MPI_DOUBLE_PRECISION,3,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(E,1,MPI_DOUBLE_PRECISION,4,2,INTERCOMM,IERROR)
                 CALL MPI_RECV(RES,1,MPI_DOUBLE_PRECISION,0,999,INTERCOMM,STATUS,IERROR)
                 PART1=MAX(PART1,RES)
              END DO
           END DO
        END DO
     END DO
  END DO

  PART2=0
  DO A=5,9
     DO B=5,9
        IF(B.EQ.A)CYCLE
        DO C=5,9
           IF(ANY((/A,B/).EQ.C))CYCLE
           DO D=5,9
              IF(ANY((/A,B,C/).EQ.D))CYCLE
              DO E=5,9
                 IF(ANY((/A,B,C,D/).EQ.E))CYCLE
                 CALL MPI_SEND(A,1,MPI_DOUBLE_PRECISION,0,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(INIT,1,MPI_DOUBLE_PRECISION,0,3,INTERCOMM,IERROR)
                 CALL MPI_SEND(B,1,MPI_DOUBLE_PRECISION,1,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(C,1,MPI_DOUBLE_PRECISION,2,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(D,1,MPI_DOUBLE_PRECISION,3,2,INTERCOMM,IERROR)
                 CALL MPI_SEND(E,1,MPI_DOUBLE_PRECISION,4,2,INTERCOMM,IERROR)
                 CALL MPI_RECV(RES,1,MPI_DOUBLE_PRECISION,0,999,INTERCOMM,STATUS,IERROR)
                 PART2=MAX(PART2,RES)
              END DO
           END DO
        END DO
     END DO
  END DO
  WRITE(*,'("Part 1: ",I0)') PART1
  WRITE(*,'("Part 2: ",I0)') PART2
  DO I=0,4
     CALL MPI_SEND(-1,1,MPI_DOUBLE_PRECISION,I,2,INTERCOMM,IERROR)
  END DO
  CALL MPI_FINALIZE(IERROR)

END PROGRAM DAY7