10 LET B$="BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM"
 20 INPUT W$
 30 FOR I=1 TO LEN W$
 40 FOR J=1 TO LEN B$ STEP 2
 50 IF B$(J)<>W$(I) AND B$(J+1)<>W$(I) THEN GOTO 100
 60 LET B$=B$( TO J-1)+B$(J+2 TO )
 70 NEXT I
 80 PRINT "YES"
 90 STOP
100 NEXT J
110 PRINT "NO"