PROGRAM square_sum
  IMPLICIT NONE
  REAL sq_sum, number
  OPEN (1, FILE = 'square.dat')
  sq_sum = 0.0                     
  DO 
    READ (1, '(F4.2)') number       
    WRITE (*, *) 'number = ', number 	
    IF (number == 0.0) EXIT     
    IF (number <  0.0) CYCLE  
    sq_sum = sq_sum + SQRT(number)
    WRITE (*,*) 'square_sum =', sq_sum
  END DO
  PRINT '(/)'
  PRINT *,'The solution is:'
  WRITE (*,*) sq_sum
END PROGRAM square_sum