import java.io.*;
import java.util.*;
public class Main
{
	public static void main(String args[])throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	}
} import java.io.*; io.* java import java.util.*; util.* java public class Main
{
	public static void main(String args[])throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	}
} Main public static void main(String args[])throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	} main {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) long n = Long.parseLong(br.readLine()); n Long.parseLong(br.readLine()) Long.parseLong Long br.readLine() br.readLine br String s=""; s "" while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		} n>0 n 0 {
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		} int x = (int)(n%26); x (int)(n%26) n 26 n = n/26 n n/26 n 26 if(x==0){
				x=26;
				n--;
			} x==0 x 0 {
				x=26;
				n--;
			} x=26 x 26 n-- n s=s+(char)(97+x-1) s s+(char)(97+x-1) s (char)(97+x-1) 97+x 97 x 1 for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i)); int i=s.length()-1; int i=s.length()-1; i s.length()-1 s.length() s.length s 1 i>=0 i 0 i-- i-- i System.out.print(s.charAt(i)); System.out.print(s.charAt(i)) System.out.print System.out System System.out s.charAt(i) s.charAt s i System.out.println() System.out.println System.out System System.out String args[] args public class Main
{
	public static void main(String args[])throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	}
} public class Main
{
	public static void main(String args[])throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	}
} Main
import java.io.*;
import java.util.*;
public class Main
{
	public static void main(String args[])throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		long n = Long.parseLong(br.readLine());
		//StringTokenizer st = new StringTokenizer(br.readLine());
	//	for(int k=1;k<=n;k++){
			//int j=k;
		String s="";
		while(n>0)
		{
			int x = (int)(n%26);
			n = n/26;
			if(x==0){
				x=26;
				n--;
			}
			s=s+(char)(97+x-1);
		}
		for(int i=s.length()-1;i>=0;i--)
			System.out.print(s.charAt(i));
		System.out.println();//}
		//System.out.println((char)(97+26-1));

	}
}