// Original C++ solution (slower):
/*

* じょえチャンネル

* 高評価・チャンネル登録よろしくおねがいします！

* https://www.youtube.com/channel/UCRXsI3FL_kvaVL9zoolBfbQ

*/



#include <bits/stdc++.h>





#define f(i,n) for(int i=0;i<(n);i++)





#define inf (int)(3e18)

#define int long long

#define mod (int)(1000000007)



#define intt long long

#define P pair<int,int>



#define rep(i,n) for(int i=0;i<n;i++)

#define REP(i,n) for(int i=1;i<=n;i++)



using namespace std;



//Library

//モッドパウ

int modpow(int x, int y, int m = mod) {

    int res = 1;

    while (y) {

        if (y % 2) {

            res *= x;

            res %= m;

        }

        x = x * x % mod;

        y /= 2;

    }

    return res;

}



int mypow(int x, int y) {

    int res = 1;

    while (y) {

        if (y % 2) {

            res *= x;

        }

        x = x * x;

        y /= 2;

    }

    return res;

}

//is the number (x) a prime number?

bool prime(int x) {

    for (int i = 2; i * i <= x; i++) {

        if (!(x % i)) {

            return false;

        }

    }

    return true;

}





//saidai-kouyakusuu

inline int gcd(int x, int y) {

    if (!y) {

        return x;

    }

    return gcd(y, x % y);

}





//number of keta

int keta(int x) {

    int ans = 0;

    while (x) {

        x /= 10;

        ans++;

    }

    return ans;

}



//sum of keta

int ketasum(int x) {

    int ans = 0;

    while (x) {

        ans += x % 10;

        x /= 10;

    }

    return ans;

}



inline int lcm(int x, int y) {

    int ans = x / gcd(x, y) * y;

    return ans;

}

int twobeki(int x) {

    int ans = 0;

    while (1) {

        if (!(x & 1)) {

            ans++;

            x /= 2;

        }

        else {

            break;

        }

    }

    return ans;

}





template <class T, class U>

inline bool chmax(T& lhs, const U& rhs) {

    if (lhs < rhs) {

        lhs = rhs;

        return 1;

    }

    return 0;

}

template <class T, class U>

inline bool chmin(T& lhs, const U& rhs) {

    if (lhs > rhs) {

        lhs = rhs;

        return 1;

    }

    return 0;

}

void Yes(){

    cout<<"Yes"<<endl;

}

void No(){

    cout<<"No"<<endl;

}

void YES(){

    cout<<"YES"<<endl;

}

void NO(){

    cout<<"NO"<<endl;

}





#define fin(i) scanf("%lld",&i)

#define fout(i) printf("%lld",i)

#define fendl printf("\n")

//Library-End



//SegTree

template <class T>

class LazySegTree {

    int n;                       // 葉の数

    vector<T> data;              // データを格納するvector

    vector<T> lazy;

    T def;                       // 初期値かつ単位元

    function<T(T, T)> operation; // 区間クエリで使う処理

    function<T(T, T)> update;    // 点更新で使う処理

    

    // 区間[a,b)の総和。ノードk=[l,r)に着目している。

    T _query(int a, int b, int k, int l, int r) {

        if (r <= a || b <= l) return def; // 交差しない

        if (a <= l && r <= b)

            return data[k]; // a,l,r,bの順で完全に含まれる

        else {

            T c1 = _query(a, b, 2 * k + 1, l, (l + r) / 2); // 左の子

            T c2 = _query(a, b, 2 * k + 2, (l + r) / 2, r); // 右の子

            return operation(c1, c2);

        }

    }

    

public:

    // _n:必要サイズ, _def:初期値かつ単位元, _operation:クエリ関数,

    // _update:更新関数

    LazySegTree(size_t _n, T _def, function<T(T, T)> _operation,

            function<T(T, T)> _update)

    : def(_def), operation(_operation), update(_update) {

        n = 1;

        while (n < _n) {

            n *= 2;

        }

        data = vector<T>(2 * n - 1, def);

    }

    

    // 場所i(0-indexed)の値をxで更新

    void change(int i, T x) {

        i += n - 1;

        data[i] = update(data[i], x);

        while (i > 0) {

            i = (i - 1) / 2;

            data[i] = operation(data[i * 2 + 1], data[i * 2 + 2]);

        }

    }

    

    void change(int i, int j, T x) {

        i += n - 1;

        data[i] = update(data[i], x);

        while (i > 0) {

            i = (i - 1) / 2;

            data[i] = operation(data[i * 2 + 1], data[i * 2 + 2]);

        }

    }

    // [a, b)の区間クエリを実行

    T query(int a, int b) {

        return _query(a, b, 0, 0, n);

    }

    

    // 添字でアクセス

    T operator[](int i) {

        return data[i + n - 1];

    }

};



#define R_MIN ([](long long a, long long b) { return min(a, b); })

#define R_MAX ([](long long a, long long b) { return max(a, b); })

#define R_SUM ([](long long a, long long b) { return a + b; })



#define NORMAL_UPDATE ([](long long a, long long b) { return b; })

#define ADD_UPDATE ([](long long a, long long b) { return a + b; })

#define MINUS_UPDATE ([](long long a, long long b) { return a - b; }







int n,m,ans;

vector<string> v[14];

signed main() {

    cin>>n;

    v[1].push_back("a");

    REP(i,n-1){

        rep(j,v[i].size()){

            int small=0;

            rep(k,v[i][j].size()){

                chmax(small, v[i][j][k]-'a');

            }

            rep(k,min(small+1ll,25ll)+1){



                string lkj=v[i][j];

                lkj.push_back('a'+k);

                v[i+1].push_back(lkj);

            }

        }

    }

    for(int i=0;i<v[n].size();i++){

        printf("%s\n",v[n][i].c_str());

    }

}






// Optimized solution to the same problem (faster):
/*

 * じょえチャンネル

 * 高評価・チャンネル登録よろしくおねがいします！

 * https://www.youtube.com/channel/UCRXsI3FL_kvaVL9zoolBfbQ

 */



#include <algorithm>

#include <bitset>

#include <cassert>

#include <cfloat>

#include <climits>

#include <cmath>

#include <complex>

#include <ctime>

#include <deque>

#include <fstream>

#include <functional>

#include <iomanip>

#include <iostream>

#include <iterator>

#include <list>

#include <map>

#include <memory>

#include <queue>

#include <random>

#include <set>

#include <stack>

#include <string>

#include <string.h>

#include <unordered_map>

#include <unordered_set>

#include <utility>

#include <vector>



//#pragma GCC target("avx2")

//#pragma GCC optimize("O3")

//#pragma GCC optimize("unroll-loops")









//here!!!

// define int long long !!!!!



#define int long long



// define int long long !!!!!





#define mod 1000000007ll

//constexpr int mod = 998244353ll;



typedef long long ll;



#ifdef int

#define inf (int)(3e18)

#else

#define inf (int)(5e8)

#endif



#define intt long long

#define itn long long

#define innt long long

#define P pair<long long,long long>



#define rep(i,n) for(int i=0;i<n;i++)

#define REP(i,n) for(int i=1;i<=n;i++)

#define rev_rep(i,n) for(int i=n-1;i>=0;i--)

#define REV_REP(i,n) for(int i=n;i>=1;i--)



#define ALL(v) v.begin(),v.end()



#define smallpriority_queue(x) priority_queue<x,vector<x>,greater<x>>



using namespace std;



//Library

//モッドパウ

inline int modpow(int x, int y, int m = mod) {

    int res = 1;

    while (y) {

        if (y & 1) {

            res *= x;

            res %= m;

        }

        x = x * x % m;

        y /= 2;

    }

    return res;

}



int mypow(int x, int y) {

    int res = 1;

    while (y) {

        if (y % 2) {

            res *= x;

        }

        x = x * x;

        y /= 2;

    }

    return res;

}

//is the number (x) a prime number?

bool prime(int x) {

    if (!x || x == 1) {

        return false;

    }

    for (int i = 2; i * i <= x; i++) {

        if (!(x % i)) {

            return false;

        }

    }

    return true;

}





//saidai-kouyakusuu

inline int gcd(int x, int y) {

    if (!y) {

        return x;

    }

    return gcd(y, x % y);

}





//number of keta

int keta(int x) {

    int ans = 0;

    while (x) {

        x /= 10;

        ans++;

    }

    return ans;

}



//number of 2shinsuu keta

int bitketa(int x) {

    int ans = 0;

    while (x) {

        x >>= 1;

        ans++;

    }

    return ans;

}



//sum of keta

int ketasum(int x) {

    int ans = 0;

    while (x) {

        ans += x % 10;

        x /= 10;

    }

    return ans;

}



inline int lcm(int x, int y) {

    int ans = x / gcd(x, y) * y;

    return ans;

}

int twobeki(int x) {

    int ans = 0;

    while (1) {

        if (!(x & 1)) {

            ans++;

            x >>= 1;

        }

        else {

            break;

        }

    }

    return ans;

}





template <class T, class U>

inline bool chmax(T& lhs, const U& rhs) {

    if (lhs < rhs) {

        lhs = rhs;

        return 1;

    }

    return 0;

}

template <class T, class U>

inline bool chmin(T& lhs, const U& rhs) {

    if (lhs > rhs) {

        lhs = rhs;

        return 1;

    }

    return 0;

}

void Yes(){

    cout<<"Yes"<<endl;

}

void No(){

    cout<<"No"<<endl;

}

void YES(){

    cout<<"YES"<<endl;

}

void NO(){

    cout<<"NO"<<endl;

}





#define fin(i) scanf("%lld",&i)

#define fout(i) printf("%lld",i)

#define fendl printf("\n")



int kai(int x, int y) {

    int res = 1;

    for (int i = x - y + 1; i <= x; i++) {

        res *= i; res %= mod;

    }

    return res;

}



int comb(int x, int y) {

    if (y > x)return 0;

    //    cout<<kai(x, y)<<' '<<modpow(kai(y, y), mod - 2)<<endl;

    return kai(x, y) * modpow(kai(y, y), mod - 2) % mod;

}

//Library-End



//入出力高速化時にはoff！！！！

//#define vecin(v) for(int i=0;i<v.size();i++)scanf("%lld",&v[i]);

//#define vecout(v) {if(v.size())printf("%lld",v[0]);for(int i=1;i<(int)v.size();i++)printf(" %lld",v[i]);printf("\n");}







template <class T>

class SegTree {

    int n;

    vector<T> node;

    T def;

    function<T(T,T)> operation;

    function<T(T,T)> update;

    

public:

    SegTree(unsigned int _n, T _def, function<T(T, T)> _operation,

            function<T(T, T)> _update)

    : def(_def), operation(_operation), update(_update) {

        n=1;

        while (n < _n) {

            n *= 2;

        }

        node = vector<T>(n * 2, def);

    }

    SegTree(vector<int>& initvec, function<T(T, T)> _operation,

            function<T(T, T)> _update)

    :  operation(_operation), update(_update) {

        n=1;

        while (n < initvec.size()) {

            n *= 2;

        }

        node = vector<T>(n * 2, def);

        for(int i=n;i<n+initvec.size();i++){

            node[i]=initvec[i-n];

        }

        for(int i=n-1;i>=1;i--){

            node[i]=operation(node[i*2],node[i*2+1]);

        }

    }

    void change(int i,T x){

        i+=n;

        node[i]=update(node[i],x);

        while (i>=1) {

            i>>=1;

            node[i]=operation(node[i*2],node[i*2+1]);

        }

    }

    T query(int l, int r){

        l+=n;

        r+=n;

        T rx=def,lx=def;

        while(l<r){

            if (l&1) {

                lx=operation(lx,node[l]);

                l++;

            }

            if (r&1) {

                r--;

                rx=operation(node[r],rx);

            }

            l>>=1; r>>=1;

        }

        return operation(lx,rx);

    }

    T operator [] (const int& x){

        return node[x+n];

    }

    void fill(T x) {

        std::fill(ALL(node), x);

    }

    void print() {

        rep(i, n)std::cout << operator[](i) << " ";

        std::cout << std::endl;

    }

    

};



#define R_MIN ([](long long a, long long b) { return min(a, b); })

#define R_MAX ([](long long a, long long b) { return max(a, b); })

#define R_SUM ([](long long a, long long b) { return a + b; })



#define NORMAL_UPDATE ([](long long a, long long b) { return b; })

#define ADD_UPDATE ([](long long a, long long b) { return a + b; })

#define MINUS_UPDATE ([](long long a, long long b) { return a - b; }



class Union_Find {

    vector<int> par;

    vector<int> rankmy;

    vector<int> ookisa;

    

public:

    Union_Find(int size) {

        par = vector<int>(size);

        rankmy = vector<int>(size);

        ookisa=vector<int>(size);

        for (int i = 0; i < size; i++) {

            par[i] = i;

            ookisa[i]=1;

        }

    }

    

    int find(int x) {

        if (par[x] == x) {

            return x;

        }

        return par[x] = find(par[x]);

    }

    

    void unite(int x, int y) {

        x = find(x);

        y = find(y);

        if (x == y) {

            return;

        }

        if (rankmy[x] < rankmy[y]) {

            par[x] = y;

            ookisa[y]+=ookisa[x];

            ookisa[x]=0;

        }

        else {

            par[y] = x;

            ookisa[x]+=ookisa[y];

            ookisa[y]=0;

            if (rankmy[x] == rankmy[y]) {

                rankmy[x]++;

            }

        }

    }

    int size(int i){

        i=find(i);

        return ookisa[i];

    }

    bool same(int x, int y){

        return find(x) == find(y);

    }

    

};



class BIT {

    vector<int> data;

    int size=0;

public:

    BIT(int _size){

        data=vector<int>(_size+1);

        size=_size;

    }

    void add(int i,int x){

        while (i<=size) {

            data[i]+=x;

            i += i & -i;

        }

    }

    int sum(int i){

        assert(i<=size);

        int s=0;

        while(i>0){

            s+=data[i];

            i -= i & -i;

        }

        return s;

    }

    int lower_bound(int x){

        if(x<=0){

            return 0;

        }else{

            int i=0;int r=1;

            while(r<size) r=r<<1;

            for(int len=r;len>0;len=len>>1) {

                if(i+len<size && data[i+len]<x){

                    x-=data[i+len];

                    i+=len;

                }

            }

            return i+1;

        }

    }

};



//Union-Find-End



int perm[2000005];

void init_perm() {

    perm[0] = 1;

    REP(i, 2000004) {

        perm[i] = perm[i - 1] * i % mod;

    }

}



int nCk(int x, int y) {

    if (y>x) {

        return 0;

    }

    if (x<0) {

        return 0;

    }

    return perm[x] * modpow(perm[x - y], mod - 2) % mod * modpow(perm[y], mod - 2) % mod;

}



double kyori(pair<int, int> f, pair<int, int> s) {

    double ans = 0;

    double t = fabs(f.first - s.first);

    double y = fabs(f.second - s.second);

    ans = sqrt(t * t + y * y);

    return ans;

}



inline string stringmax(string& x,string& y){

    if (x.size()>y.size()) {

        return x;

    }

    if (x.size()<y.size()) {

        return y;

    }

    rep(i,x.size()){

        if (x[i]>y[i]) {

            return x;

        }

        if (x[i]<y[i]) {

            return y;

        }

    }

    return x;

}



//vector<int>  RollingHash(string &s, string& t){

//    vector<int> ans;

//    __int128 h=0,hamod=0,ki=0,kim=0,hikaku=0,one=0;

//    one=1;

//    ki=1000000007ll;

//    hamod=(one<<61)-1;

//    kim=1;

//    rep(i,t.size()){

//        hikaku*=ki;

//        h*=ki;

//        kim*=ki;

//        hikaku+=t[i];

//        h+=s[i];

//        hikaku%=hamod;

//        h%=hamod;

//        kim%=hamod;

//    }

//    rep(i,(int)s.size()-(int)t.size()+1){

//        if (h==hikaku) {

//            ans.emplace_back(i);

//        }

//        h*=ki;

//        h%=hamod;

//        h+=s[i+(int)t.size()];

//        h%=hamod;

//        h+=hamod;

//        h-=s[i]*kim%hamod;

//        h%=hamod;

//    }

//    return ans;

//}

struct edge {

    int to;

    int length;

    edge(int _to, int _length){

        to=_to;

        length=_length;

    }

};

vector<int> djkstra(vector<vector<edge>> &road,int start){

    vector<int> kyo(road.size(),inf);

    smallpriority_queue(P) q;

    q.push({0,start});

    kyo[start]=0;

    while (q.size()) {

        int x=q.top().second;

        itn now=q.top().first;

        q.pop();

        if (kyo[x]<now) {

            continue;

        }

        for(auto&i:road[x]){

            if (kyo[i.to]>now+i.length) {

                kyo[i.to]=now+i.length;

                q.push({kyo[i.to],i.to});

            }

        }

    }

    return kyo;

}



template <class T>

void change_to_unique(vector<T> &v){

    std::sort(ALL(v));

    auto k=unique(ALL(v));

    if(k!=v.end())v.erase(k,v.end());

}



#define endl "\n" //interactive の時に注意！！！

#define Endl "\n" //interactive の時に注意！！！

#define cinn cin

#define printd cout<<fixed<<setprecision(10)

#define rrep(i,f,s) for(int i=f;i<s;i++)

#define RREP(i,f,s) for(int i=f;i<=s;i++)

#define REV_RREP(i,f,s) for(int i=s;i>=f;i--)

#define hen_rep(i,l,step) for(int i=0;i<l;i+=step)

#define HEN_REP(i,l,step) for(int i=1;i<=l;i+=step)



string s;

int n;

void solve(string &s, int bg){

    if (s.size()==n) {

        cout<<s<<endl;

    }else{

        rep(i,bg+2){

            s.push_back('a'+i);

            solve(s,max(bg,i));

            s.pop_back();

        }

    }

}

signed main() {

    ios::sync_with_stdio(false);

    std::cin.tie(nullptr);

    cin>>n;

    solve(s, -1);

}


















// Fastest known solution for this problem: