5 PRINT "A,B,Z,N? (TO END PROGRAM INPUT 0,0,0,0)"
10 INPUT A,B,Z,N
15 IF A^2+B^2=0 THEN 99
20 S=1 
25 FOR I=N TO 1 STEP -1
30 S=1+(A+I-1)*Z*S/((B+I-1)*I) 
35 NEXT I
40 PRINT "M=";S
45 PRINT 
50 PRINT "A,B,Z,N?"
55 GOTO 10 
99 END 

