AoC 2019 Day3 FORTRAN

PROGRAM DAY3
  INTEGER :: N,L,I,J,K,IERR,X,Y,MAXX=0,MAXY=0,MINX=0,MINY=0,T,STEP
  INTEGER :: X1,X2,Y1,Y2
  CHARACTER(LEN=9),ALLOCATABLE :: INPUTA(:),INPUTB(:)
  CHARACTER(LEN=:), ALLOCATABLE :: INLINE
  CHARACTER(LEN=1) :: CHAR
  INTEGER, ALLOCATABLE :: WIREA(:,:),WIREB(:,:),DIST(:,:)
  OPEN(1,FILE="input.txt")
  L=0
  N=1
  DO
     READ(1,'(A)',ADVANCE="NO",IOSTAT=IERR)CHAR
     IF(IERR.NE.0)EXIT
     L=L+1
     IF(CHAR.EQ.',')N=N+1
  END DO
  ALLOCATE(INPUTA(N))
  ALLOCATE(CHARACTER(LEN=L) :: INLINE)

  REWIND(1)
  READ(1,'(A)')INLINE
  I=1
  DO J=1,N-1
     INPUTA(J)=INLINE(I:I+SCAN(INLINE(I:),",")-2)
     I=I+SCAN(INLINE(I:),",")
  END DO
  INPUTA(N)=INLINE(I:)
  DEALLOCATE(INLINE)

  REWIND(1)
  L=0
  N=1
  READ(1,*)
  DO
     READ(1,'(A)',ADVANCE="NO",IOSTAT=IERR)CHAR
     IF(IERR.NE.0)EXIT
     L=L+1
     IF(CHAR.EQ.',')N=N+1
  END DO
  ALLOCATE(INPUTB(N))
  ALLOCATE(CHARACTER(LEN=L) :: INLINE)

  REWIND(1)
  READ(1,*)
  READ(1,'(A)')INLINE
  I=1
  DO J=1,N-1
     INPUTB(J)=INLINE(I:I+SCAN(INLINE(I:),",")-2)
     I=I+SCAN(INLINE(I:),",")
  END DO
  INPUTB(N)=INLINE(I:)
  CLOSE(1)

  X=0
  Y=0
  DO I=1,SIZE(INPUTA)
     READ(INPUTA(I)(2:),*)J
     SELECT CASE (INPUTA(I)(1:1))
     CASE ("U")
        Y=Y+J
        MAXY=MAX(MAXY,Y)
     CASE ("D")
        Y=Y-J
        MINY=MIN(MINY,Y)
     CASE ("R")
        X=X+J
        MAXX=MAX(MAXX,X)
     CASE ("L")
        X=X-J
        MINX=MIN(X,MINX)
     END SELECT
  END DO
  X=0
  Y=0
  DO I=1,SIZE(INPUTB)
     READ(INPUTB(I)(2:),*)J
     SELECT CASE (INPUTB(I)(1:1))
     CASE ("U")
        Y=Y+J
        MAXY=MAX(MAXY,Y)
     CASE ("D")
        Y=Y-J
        MINY=MIN(MINY,Y)
     CASE ("R")
        X=X+J
        MAXX=MAX(MAXX,X)
     CASE ("L")
        X=X-J
        MINX=MIN(X,MINX)
     END SELECT

  END DO
  ALLOCATE(WIREA(MINX:MAXX,MINY:MAXY),WIREB(MINX:MAXX,MINY:MAXY),DIST(MINX:MAXX,MINY:MAXY))
  WIREA=0
  WIREB=0
  DO Y=MINY,MAXY
     DO X=MINX,MAXX
        DIST(X,Y)=ABS(X)+ABS(Y)
     END DO
  END DO

  T=0
  X=0
  Y=0
  DO I=1,SIZE(INPUTA)
     READ(INPUTA(I)(2:),*)K
     DO J=1,K
        T=T+1
        SELECT CASE (INPUTA(I)(1:1))
        CASE ("U")
           Y=Y+1
        CASE ("D")
           Y=Y-1
        CASE ("L")
           X=X-1
        CASE ("R")
           X=X+1
        END SELECT
        WIREA(X,Y)=T
     END DO
  END DO

  T=0
  X=0
  Y=0
  DO I=1,SIZE(INPUTB)
     READ(INPUTB(I)(2:),*)K
     DO J=1,K
        T=T+1
        SELECT CASE (INPUTB(I)(1:1))
        CASE ("U")
           Y=Y+1
        CASE ("D")
           Y=Y-1
        CASE ("L")
           X=X-1
        CASE ("R")
           X=X+1
        END SELECT
        WIREB(X,Y)=T
     END DO
  END DO

  WRITE(*,'("Part 1: ",I0)') MINVAL(DIST,MASK=(WIREA>0.AND.WIREB>0.AND.DIST>0))
  WRITE(*,'("Part 2: ",I0)') MINVAL(WIREA+WIREB,MASK=(WIREA>0.AND.WIREB>0))

END PROGRAM DAY3