// dfmt off
T lread(T=long)(){return readln.chomp.to!T;}T[] lreads(T=long)(long n){return iota(n).map!((_)=>lread!T).array;}
T[] aryread(T=long)(){return readln.split.to!(T[]);}void arywrite(T)(T a){a.map!text.join(' ').writeln;}
void scan(L...)(ref L A){auto l=readln.split;foreach(i,T;L){A[i]=l[i].to!T;}}alias sread=()=>readln.chomp();
void dprint(L...)(lazy L A){debug{auto l=new string[](L.length);static foreach(i,a;A)l[i]=a.text;arywrite(l);}}
static immutable MOD=10^^9+7;alias PQueue(T,alias l="b<a")=BinaryHeap!(Array!T,l);import std, core.bitop;
// dfmt on

void main()
{
    long N = lread();
    alias T = Tuple!(long, char[]);
    DList!T Q;
    Q.insert(T(1, repeat('a').take(N).array()));
    while (!Q.empty)
    {
        auto t = Q.front;
        Q.removeFront();
        if (t[0] == N)
        {
            writeln(t[1]);
            continue;
        }
        char c = 'a';
        foreach (i; 0 .. t[0])
            if (c < t[1][i])
                c = t[1][i];
        foreach (char x; 'a' .. cast(char)(c + 2))
        {
            auto s = t[1].dup;
            s[t[0]] = x;
            Q.insertBack(T(t[0] + 1, s));
        }
    }
}
