Dear Sir/Madam,

I have a combination of following letters

bbbb,bbbc,bbbh,bbcb,bbcc,bbch,bbhb,bbhc,bbhh,bcbb,bcbc,bcbh,bccb,bccc,bcch,bchb,bchc,bchh,bhbb,bhbc,bhbh,bhcb,bhcc,bhch,bhhb,bhhc,bhhh,cbbb,cbbc,cbbh,cbcb,cbcc,cbch,cbhb,cbhc,cbhh,ccbb,ccbc,ccbh,cccb,cccc,ccch.

And I want to eliminate those combinations which at least do not contain b,c,h such as bbbb, bbbc, etc.

Kindly help with the following problem.

Thanks in advance.....