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                                                                             
