program XTON

implicit none

REAL :: x

INTEGER :: n

print *, "Enter x followed by n"

READ *, x, n

PRINT *, x, "power", n, " is: ", XpowerN(x,n)

CONTAINS

RECURSIVE FUNCTION XpowerN(x,n) RESULT(xn)

REAL :: xn

REAL, INTENT(IN) :: x

INTEGER, INTENT(IN) :: n

INTEGER :: m

m=abs(n)

IF (m==0) THEN

xn=1

ELSE

xn=x*XpowerN(x,m-1)

END IF

IF (n<0) THEN

xn=1.0/xn

END IF

END FUNCTION XpowerN

end program XTON