10 INPUT X:X$=STR$(X)
20 K=0
30 FOR J=2 TO LEN(X$)
40 P=0
50 FOR I=2 TO LEN(X$)
60 IF MID$(X$,J,1)=MID$(X$,I,1) THEN P=P+1
70 NEXTI
80 IF P=1 THEN K=K+1
90 NEXTJ
100 PRINT "K=";K