#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;
typedef vector<int> vint;
typedef pair<int,int> pint;
typedef vector<pint> vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define all(v) (v).begin(),(v).end()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
const int MOD = 1e9 + 7;
const int INF = 1e9;

int n;
int cnt = 0;
string s = "";
void pri(int t){
	s += 'a' + 2 * cnt;
	s += 'b' + 2 * cnt;
	s += 'a' + 2 * cnt;
	rep(i, t - 1){
		s += 'b' + 2 * cnt;
		s += 'a' + 2 * cnt;
	}
	return;
}

void pri2(int t, int nokori){
	string s = "iwi";
	rep(i, t - 1){
		s += "wi";
	}
	rep(i, nokori){
		if(i % 3 == 1) s += 'a';
		else if(i % 3 == 2) s += 'b';
		else s += 'c';
	}
	cout << s << endl;
}

int main(void){
	cin >> n;
	if(n == 1){
		cout << "a" << endl;
	}else if(n == 2){
		cout << "ab" << endl;
	}else if(n == 3){
		cout << "abc" << endl;
	}else{
		while(n > 0){
			int i = 0;
			int len = 1;
			while(i * i + len <= n && n >= 4){
				i++;
				len += 2;
			}
			// printf("i %d\n", i);
			if(i != 0){
				pri(i - 1);
				cnt++;
				// printf("%d %d %d\n", n, i, len);
				n -= (i - 1) * (i - 1) + len - 2;
				// printf("%d \n", n);
			}else{
				break;
			}
		}

		rep(i, n){
			if(i % 3 == 0) s += 'x';
			else if(i % 3 == 1) s += 'y';
			else s += 'z';
		}
	}
	cout << s << endl;
	return 0;
}