/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.05.25 01:14:43
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    int n;cin >> n;
    ll k = 0;
    while((k + 2)*(k + 2) <= n) {
        k++;
    }
    string s;
    ll cnt = (k+1)*(k+1);
    for (int i = 0; i < k; i++) {
        s += "ab";
    }
    s += "a";
    ll k2 = 0;
    while((k2 + 2)*(k2 + 2) <= n - cnt) {
        k2++;
    }
    if (cnt == n) {
        cout << s << endl;
        return 0;
    }
    ll cnt2 = (k2+1)*(k2+1);
    for (int i = 0; i < k2; i++) {
        s += "cd";
    }
    s += "c";
    for (ll i = cnt + cnt2; i < n; i++) {
        s += "e";
        i++;
        if (i < n) {
            s += "f";
            i++;
        }
        if (i < n) {
            s += "g";
            i++;
        }
    }
    //cout << s.size() << endl;
    cout << s << endl;
    return 0;
}