#include<cstdio>
#include<queue>
#include<utility>
#include<cstring>
#include<stack>
#include<algorithm>
#include<cmath>
#include<iostream>
#include<map>
#define MAX_N 100001
#define INF_INT 2147483647
#define INF_LL 9223372036854775807
#define REP(i,n) for(int i=0;i<(int)(n);i++)
void init(int n);
int find(int n);
void unite(int x,int y);
bool same(int x, int y);
int dx[4] = {1,0,0,-1};
int dy[4] = {0,1,-1,0};
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
bool cmp_P(const P &a,const P &b){
  return a.second < b.second;
}
int main()
{
  int N;
  cin >> N;
  string s = "aaaaaaaaaaaaaaaaaa",ori;
  ori = s;
  for(int i=0;i < 1 << 18;i++){
    if(i+1 == N){
      cout << "an" << endl;
      return 0;
    }else{
      REP(j,19){
        if((i >> j) & 1){
          s[j] += 1;
        }
      }
      cout << "a"+s+"a" << endl;
      s = ori;
    }
  }
  cout << N << endl;
  return 0;
}

int par[MAX_N];
int ranks[MAX_N];

//n要素で初期化
void init(int n){
  REP(i,n){
    par[i] = i;
    ranks[i] = 0;
  }

}

//木の根を求める
int find(int x){
  if(par[x] == x){
    return x;
  }else{
    return par[x] = find(par[x]);
  }
}

void unite(int x,int y){
  x = find(x);
  y = find(y);
  if(x == y) return ;
  if(ranks[x] < ranks[y]){
    par[x] = y;
  }else{
    par[y] = x;
    if(ranks[x] == ranks[y]) ranks[x]++;
  }
}

bool same(int x, int y){
  return find(x) == find(y);
}