import java.util.*; class Main { public static void main(String[] args) { Scanner scan = new Scanner(System.in); long n=scan.nextLong(); String[] d=new String[32]; int p=1; for(int i=0;i<20;++i){ d[i]=Character.toString((char)(97+i)); } for(int i=20;i<32;++i){ int x=(i-20)/4; int y=(i-20)%4; char[] k={(char)(97+20+x),(char)(97+24+y)}; d[i]=new String(k); } String c="a"; StringBuilder sb=new StringBuilder(); StringBuilder rev=new StringBuilder(); int h=-1; for(int i=30;i>=0;--i){ if(1L<n){continue;} h=i;break; } for(int i=h-1;i>=0;--i){ //2bai sb.append(c); rev.append(new StringBuilder(c).reverse()); //+1 if((n&1<