Supposedly i need to write a 20 word long sentence in order to ask this question so here

Try d cause last i guessed that and it was right

As you know john locke said he wanted life liberty and the pursuit of happiness so thomas jefferson was inspired about what john locke said so thomas jefferson wrote the declaration of independence for people to be free for people to be happy

Oh yeah yeah the answer is oh yeah yeah

I’m not absolutely sure but i think it’s 7x6x5x4x3x2=5040 because as the first character you can take any of the 7 given then you are left with 5 then 6 then 4 etc.