#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#include<cassert>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (Y);++(X))
#define rrep(X,Y) for (int (X) = (Y)-1;(X) >=0;--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()
#define eb emplace_back
#define UNIQUE(X) (X).erase(unique(all(X)),(X).end())

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<class T> using vv=vector<vector<T>>;
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"{"; rep(i,t.size()) {os<<t[i]<<",";} os<<"}"<<endl; return os;}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
const ll MOD=1e9+7;

int main(){
  ios_base::sync_with_stdio(false);
  cout<<fixed<<setprecision(0);
  vector<ll> sq(1e5);
  rep(i,1e5)
    sq[i]=1ll*i*i;
  int n,m;
  string re;
  vector<string> str;
  rrep(i,13){
    string tmp="ab";
    rep(j,2)tmp[j]+=i*2;
    str.pb(tmp);
  }
  //cout<<str<<endl;
  cin>>n;
  rep(i,26){assert(i<13);
    m=upper_bound(all(sq),n)-sq.begin()-1;
    //cout<<n<<":"<<*lower_bound(all(sq),n)<<endl;
    rep(j,m-1)re+=str[i];
    //cout<<pii(n,m)<<endl;
    re+=str[i][0];
    if(!(n-=m*m)) break;
  }
  cout<<re<<endl;
  assert(re.size()<=100000);
  return 0;
}