#include <bits/stdc++.h>
#define rep(i, a) for (int i = 0; i < (a); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) for (int i = (a) - 1; i >= 0; i--)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
using namespace std;
typedef long long ll;
const ll inf = 1e9;
const ll mod = 1e9 + 7;

ll f(ll x) {
    if (x % 2 == 0) {
        return (x + 0) * (x / 2 + 1) / 2;
    } else {
        return (x + 1) * (x / 2 + 1) / 2;
    }
}

int main() {
    ll N;
    cin >> N;

    string ans;

    for (char c = 'a'; N > 0 && c <= 'z'; c += 2) {
        ll l = 0;
        ll r = 1000000;

        while (r - l > 1) {
            ll m = (l + r) / 2;
            
            if (f(m) <= N) {
                l = m;
            } else {
                r = m;
            }
        }

        N -= f(l);
        rep (i, l) {
            if (i % 2 == 0) {
                ans += c;
            } else {
                ans += c + 1;
            }
        }
    }

    if (N > 0) {
        cout << "toro" << endl;
    } else {
        cout << ans << endl;
    }
}