PROGRAM Call_airfoil
IMPLICIT NONE
REAL (KIND=8), ALLOCATABLE  :: x(:), y(:), L(:), S(:), C(:), xbar(:), ybar(:), NCON(:,:)
INTEGER                                         ::      N, i, m, p, tt

N = 200

OPEN(13, FILE="xy.dat")

ALLOCATE(X(N), Y(N), L(N), S(N), C(N), xbar(N), ybar(N), NCON(N,2))

WRITE (*,*) "ENTER NACA 4-digit Code"
READ (*,"(I1,I1,I2)") m, p, tt

DO i=1, 3
        WRITE (*,*) "ENTER NUMBER OF SUBSECTIONS"
        READ (*,*) N
        IF (MOD(N,2) == 0) THEN
                EXIT
        ELSE
                WRITE(*,"(A,2/)") "ERROR: N must be even"
        ENDIF
ENDDO
WRITE(*,*) N

CALL AIRFOIL_BUILDER(N,m,p,tt,x,y)

WRITE(*,*) N
do i=1, N
        NCON(i,1) = i
        NCON(i,2) = i+1
end do
NCON(N,2) = 1

CALL ELEMENT_PROPERTIES(x, y, N,NCON, L, S, C, xbar, ybar)

WRITE (*,*) N

WRITE(13,"(3(A,/),A,(I4,/), (A,/))") "tecplot", "VARIABLE = 'i', 'x', 'y'", "ZONE T='Position'", "I=", N, "F=Point"
DO i=1,N
        WRITE(13,*) i, x(i), y(i)
ENDDO
CLOSE(13)

END PROGRAM