N=10
s=fill(Char(97),N)
sp=fill(0,N)
i=0
flag=true
re=[]
while sp[N]==0
    #print.(reverse(s.+sp))
    push!(re,reverse(s.+sp)...)
    sp[1]+=1
    for i in 1:(N-1)
        if sp[i]==N
            sp[i+1]+=1
            for j in i:-1:1
                sp[j]=sp[i+1]
            end
        end
    end
    #flag && print("\n")
    flag && push!(re,Char(10))
end
print.(re)