#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>

#define FORR(i,b,e) for(int i=(b);i<(int)(e);++i)
#define FOR(i,e) FORR(i,0,e)
#define sortuniq(v) sort(v.begin(), v.end()), v.erase(unique(v.begin(),v.end()),v.end())
#define dump(var) cerr << #var ": " << var << "\n"
#define dumpc(con) for(auto& e: con) cerr << e << " "; cerr<<"\n"

typedef long long ll;
typedef unsigned long long ull;

const double EPS = 1e-6;
const int d4[] = {0, -1, 0, 1, 0};

using namespace std;

void _p(const int &N) {
    int s = 0;
    for (int n = N; n > 0; n-=2) {
        s += n;
    }
    cout << s << endl;

    double x = N;
    cout << (x*x + (N&1))/4 + x/2 << endl;
}

void solve(const int &N) {
    int n = N;
    char c1 = 'a', c2 = 'b';
    while (n > 0) {
        ll l = (int)sqrt(4.0 * n) - 1;
        for (int i=l; i>1; i-=2) cout << c1 << c2;
        if (l&1) cout << c1;
        c1 += 2;
        c2 += 2;
        n -= (double)(l*l+(l&1))/4 + l/2;
    }
    cout << endl;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N;
    cin >> N;
    solve(N);

    return 0;
}