#include <bits/stdc++.h>
#include <string>
#define ft first
#define sc second
#define pt(sth) cout << sth << "\n"
#define chmax(a, b) (a)=max(a, b)
#define chmin(a, b) (a)=min(a, b)
#define moC(a, s, b) (a)=((a)s(b)+MOD)%MOD
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
static const ll INF=1e18;
static const ll MAX=101010;
static const ll MOD=1e9+7;

/*
 for(i=0; i<N; i++)
   cin >> a[i];
*/

ll N;
ll cnt=1;

void dfs(vector<char> c, ll k) {
  if(cnt>N) return;
  cnt++;
  
  for(auto cc:c) cout << cc;
  pt("");
  
  for(char p='b'; p<='z'; p++) {
    c[k]=p;
    dfs(c, k+1);
  }
  
  
}

int main(void) {
  ll i, j, k;

  cin >> N;
  
  vector<char> c(20);
  c[0]='n'; c[19]='n';
  for(i=1; i<19; i++) c[i]='a';
  dfs(c, 1);
  
}