/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.05.25 00:56:58
**/

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

int main() {
    int n;cin >> n;
    ll k = 0;
    while((k + 1) * (k + 2) / 2 <= n) {
        k++;
    }
    ll cnt = k * (k + 1) / 2;
    for (int i = 0; i < k; i++) {
        cout << "a";
    }
    for (ll i = cnt; i < n; i++) {
        cout << "b";
        i++;
        if (i < n) {
            cout << "c";
            i++;
        }
        if (i < n) {
            cout << "d";
            i++;
        }
    }
    return 0;
}