PROGRAM SCK1
      T=0.499975                                            
      I = 1
      N1=0                                                  
      X1=1.0                                                
      X2=-1.0                                               
      X3=-1.0                                               
      X4=-1.0                                               
      IF(N1)19,19,11                                        
   11 DO 18 I=1,N1,1                                        
      X1=(X1+X2+X3-X4)*T                                    
      X2=(X1+X2-X3+X4)*T                                    
      X3=(X1-X2+X3+X4)*T                                    
      X4=(-X1+X2+X3+X4)*T                                   
   18 CONTINUE                                              
   19 CONTINUE                                              
      END