MODULE common
    IMPLICIT NONE
    REAL data
END MODULE common

REAL FUNCTION value (arg)
    USE common
    IMPLICIT NONE
    REAL arg
    value = (arg-data)**3
END FUNCTION value

REAL FUNCTION derivative (arg)
    USE common
    IMPLICIT NONE
    REAL arg
    derivative = 3*(arg-data)**2
END FUNCTION derivative

PROGRAM main
    USE common
    IMPLICIT NONE
    REAL location
    REAL, EXTERNAL :: value, derivative
    REAL, DIMENSION(5) :: previous
    INTEGER :: i
    READ (*,*) data
    location = 0.0
    DO i = 1,5
        previous(i) = 0.0
    END DO
    DO
        location = location - value(location)/derivative(location)
        WRITE (*,'(F20.16,F20.16,F20.16)') location
        DO i = 1,5
            if (location .EQ. previous(i)) GOTO 10
        END DO
        DO i = 1,4
            previous(i+1) = previous(i)
        END DO
        previous(5) = location
    END DO
10  CONTINUE
END PROGRAM main