import java.util.Scanner;
public class Main {
public static void main (String [] args){
Scanner lukija = new Scanner(System.in);
int apu = Integer.valueOf(lukija.nextLine());
int apu2 = 0;
String eka = a;
while(apu2<apu+1){
if(apu == 1){
eka = "b" + eka + "b";
}
if(apu == 2){
eka = "c" + eka + "c";
}
if(apu == 3){
eka = "d" + eka + "d";
}
if(apu == 4){
eka = "e" + eka + "e";
}
if(apu == 5){
eka = "f" + eka + "f";
}
if(apu == 6){
eka = "g" + eka + "g";
}
if(apu == 7){
eka = "h" + eka + "h";
}
apu2++;
}
System.out.println(eka);
}
}