#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

using namespace std;
using i64 = int64_t;
using vi = vector<i64>;
using vvi = vector<vi>;
constexpr i64 MOD = 1000000000;

string construct(long long n, bool a, long long& res) {
    string ret = "";
    long long l = 0, r = n + 1;
    while (l < r - 1) {
        long long m = (l + r) / 2;
        if (m * m <= n) {
            l = m;
        } else {
            r = m;
        }
    }
    
    for (int i = 0; i < 2 * l - 1; i++) {
        ret += ((i % 2 == 0) ^ a ? "a" : "b");
    }
    res = n - l * l;
    return ret;
}

int main() {
    long long n;
    cin >> n;
    
    string ans;
    long long res = n;
    bool a = true;
    int hoge = 0;
    while (res) {
        ans += construct(res, a, res);
        a = !a;
        if (res > 0) {
            ans += 'c' + (hoge++ % 24);
            res--;
        }
    }
    cout << ans << endl;
}