#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<to;x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

int N;

int step='a';

void go(int hoge) {
	
	int i;
	FOR(i,hoge-1) _P("%c%c",step,step+1);
	_P("%c",step);
	
	
	step += 2;
	if(step>'z') step='a';
}

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N;
	while(N) {
		ll a;
		for(a=1;a*(a+1)/2+(a-1)*(a)/2<=N;a++);
		a--;
		go(a);
		N -= a*(a+1)/2+(a-1)*(a)/2;
	}
	
	_P("\n");
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false);
	FOR(i,argc-1) s+=argv[i+1],s+='\n';
	FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	solve(); return 0;
}