#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define rep(i,s,e) for(int (i) = (s);(i) <= (e);(i)++)

int N;
int rec(char c,string s,int cnt){
  if(cnt == 0){
    cout << c << s;
    N--;
    if(N == 0) cout << 'n' << endl;
    else cout << c << endl;
    return 0;
  }
  for(char a = 'a';a <= 'z';a++){
    s.push_back(a);
    rec(c,s,cnt - 1);
    s.pop_back();
    if(N == 0) return 0;
  }
  return 0;
}

int main(){
  cin >> N;
  rec('a',string(),18);
}