import java.util.*; 
import java.lang.*; 


public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        }
                
} import java.util.*; util.* java import java.lang.*; lang.* java public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        }
                
} Main public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        } main {
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long N = scan.nextLong(); N scan.nextLong() scan.nextLong scan char[] alpha = new char[26]; alpha new char[26] 26 for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                } int i = 0; int i = 0; i 0 i < 26 i 26 i++ i++ i {
                    alpha[i] = (char)(97 + i);
                } {
                    alpha[i] = (char)(97 + i);
                } alpha[i] = (char)(97 + i) alpha[i] alpha i (char)(97 + i) 97 i ArrayList<Character> ans = new ArrayList<>(); ans new ArrayList<>() while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                } N>=1 N 1 {
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                } long a = N%26; a N%26 N 26 int b = (int) a; b (int) a if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    } b!=0 b 0 {
                        ans.add(alpha[b-1]);
                    } ans.add(alpha[b-1]) ans.add ans alpha[b-1] alpha b-1 b 1 if(b==0){
                        ans.add(alpha[25]);
                    } b==0 b 0 {
                        ans.add(alpha[25]);
                    } ans.add(alpha[25]) ans.add ans alpha[25] alpha 25 if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    } N%26!=0 N%26 N 26 0 {
                        N=N/26;
                    } N=N/26 N N/26 N 26 {
                        N=N/26-1;
                    } N=N/26-1 N N/26-1 N/26 N 26 1 for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                } int i=ans.size()-1; int i=ans.size()-1; i ans.size()-1 ans.size() ans.size ans 1 i>=0 i 0 i-- i-- i {
                    System.out.print(ans.get(i));
                } {
                    System.out.print(ans.get(i));
                } System.out.print(ans.get(i)) System.out.print System.out System System.out ans.get(i) ans.get ans i String[] args args public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        }
                
} public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        }
                
} Main
import java.util.*; 
import java.lang.*; 


public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
                
                long N = scan.nextLong();
                
                char[] alpha = new char[26];
                for(int i = 0; i < 26; i++){
                    alpha[i] = (char)(97 + i);
                }
                
                ArrayList<Character> ans = new ArrayList<>();
                while(N>=1){
                    long a = N%26;
                    int b = (int) a;
                    if(b!=0){
                        ans.add(alpha[b-1]);
                    }else if(b==0){
                        ans.add(alpha[25]);
                    }
                    
                    if(N%26!=0){
                        N=N/26;
                    }else{
                        N=N/26-1;
                    }
                }
                
                for(int i=ans.size()-1; i>=0; i--){
                    System.out.print(ans.get(i));
                }
        }
                
}
