#include<bits/stdc++.h>
#define rep(i,n,m) for(int i = (n); i <(m); i++)
#define rrep(i,n,m) for(int i = (n) - 1; i >=(m); i--)
using namespace std;
using ll = long long;
const int MAXS = 100000;

vector<ll> triangle;
void init()
{
    triangle.assign(MAXS, 0);
    rep(i, 0, MAXS) triangle[i] = (ll)i * (i+1) / 2;
}

int main()
{
    init();
    ll n;
    cin >> n;
    if (n == 2 or n == 4)
    {
        cout << "maguro" << endl;
        return 0;
    }

    vector<ll>::iterator itr = upper_bound(triangle.begin(), triangle.end(), n);
    --itr;

    int num_a = itr - triangle.begin();
    int num_other = n - *itr;
    // cout << num_as << ' ' << num_other << endl;

    if (num_other % 2 == 1)
    {
        --itr;
        num_a = itr - triangle.begin();
        num_other = n - *itr;
    }


    rep(i, 0, num_a) printf("a");
    while (num_other > 0)
    {
        printf("%c", 'b' + num_other%25);
        num_other -= 2;
    }
    cout << endl;
    return 0;
}