       WRITE (6,100)
10     READ (5,200) X,Y,Z
       IF(X) 20,50,20
20     D = SQRT(X**2+Y**2+Z**2)
       WRITE (6,300) X,Y,Z,D
       GO TO 10
            50     ATOP    STOP
100    FORMAT (7X,1HX,11X,1HY,11X,1HZ,1HD)
200    FORMAT (3E)
300    FORMAT (4(1X,E11.3))
       END

