A=1                           
B=1                           
FIB=1                         
I=3                           
INPUT N                       
IF N<I                        
PRINT FIB                     
RTN                           
ENDIF                         
DO                            
A=A+B                         
FIB=A                         
IF I=N                        
EXIT                          
ENDIF                         
I=I+1                         
B=A+B                         
FIB=B                         
IF I=N                        
EXIT                          
ENDIF                         
I=I+1                         
ENDDO                         
PRINT FIB                     
