#include<bits/stdc++.h>
#define ls rt<<1
#define rs rt<<1|1
#define lson rt<<1,l,M
#define rson rt<<1|1,M+1,r
#define PI acos(-1)
#define MM int M=(l+r)>>1;
#define fu(i,r,t) for(int i=r;i<=t;i++)
#define fd(i,r,t) for(int i=r;i>=t;i--)
#define fh(i,be,e) for(int i=head[be];~i;i=e[i].next)
#define fa(i,V) for(auto i:V)
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define int long long
#define endl '\n'
#define lcm(a,b) (a*b)/__gcd(a,b)
#define cp(i,ans) printf("%.if",ans);
#define cpp(i,ans) cout<<setprecision(i)<<fixed<<ans<<endl;
#define ppb pop_back
#define ppf pop_front
#define pb push_back
#define pf push_front
#define pq priority_queue
#define lowbit(x) (x)&(-x)
#define all(V) V.begin(),V.end()
#define ms multiset
#define mod(x) ((x+mo_num)%mo_num)
#define vc vector
#define vct vector<int>
#define out(i) cout<<(i)<<endl;
#define fi first
#define se second
#define fun(i) fu(i,1,n)
#define fut(i) fu(i,1,t)
#define fum(i) fu(i,1,m)
#define ld long double
#define umap unordered_map
#define P pair<int,int>
#define SET set<int>
#define mp map<int,int>
#define mk make_tuple
#define got(container,num) get<num-1>(container)
#define low lower_bound
#define upp upper_bound
#define yn(key) out(key?"YES":"NO")
#define in(i) i+1,i+1+n
#define im(i) i+1,i+1+m
using namespace std;
const int INF=LLONG_MAX-1e10;
const int maxn=1e6+1e5;
const int mo_num=1e9+7;
int n,m,a[maxn],b[maxn],ans;
map<int ,vc<string>>h[maxn];
main()
{
    IOS
    cin>>n;
    h[1][(int)'a'].pb("a");
    fun(i)
    {
        if(i==1)continue;
        fu(j,'a','a'+i-1)
        {
            if(j=='a')
            {
                fu(k,j,'a'+i-2)
                {
                    fa(l,h[i-1][k])h[i][j].pb(l+(char)j);
                }
            }else {
                fu(k, j - 1, 'a' + i - 2) {
                    fa(l, h[i - 1][k])h[i][j].pb(l + (char) j);
                }
            }
        }
    }
    fa(i,h[n])
    {
        fa(j,i.second)
        {
            out(j)
        }
    }
    return 0;
}
