10 READ N,I
20 LET B=1
30 FOR K = 1 TO I
40     LET B = B*(N-K+1)/K
50 NEXT K
60 PRINT B
90 DATA 30,0
99 END
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           