#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;
  set<string> ss;
  random_device rd;
  mt19937 mt(rd());
  auto gen=
    [&](Int n){
      string s;
      for(Int i=0;i<n;i++) s+='a'+mt()%26;
      return s;
    };
  string s="a";
  for(Int i=0;i<n;i++){
    string t=s.back()+gen(10);
    while(ss.count(t)||t.back()=='n') t=s.back()+gen(10);    
    if(i+1==n) t+='n';
    cout<<t<<endl;    
    s=t;
    ss.emplace(s);
  }
  return 0;
}