
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
 
public class Main {    
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    }
} import java.util.ArrayList; ArrayList java.util import java.util.Arrays; Arrays java.util import java.util.HashMap; HashMap java.util import java.util.List; List java.util import java.util.Map; Map java.util import java.util.Scanner; Scanner java.util public class Main {    
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    } main {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc String[] list = new String[26]; list new String[26] 26 char temp = 'a'; temp 'a' for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        } int i=0; int i=0; i 0 i<26 i 26 i++ i++ i {
            list[i] = String.valueOf(temp++);
        } {
            list[i] = String.valueOf(temp++);
        } list[i] = String.valueOf(temp++) list[i] list i String.valueOf(temp++) String.valueOf String temp++ temp String ans = ""; ans "" while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        } 0<n 0 n {
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        } n-- n int mod = (int)( n % 26 ); mod (int)( n % 26 ) n 26 ans =ans +  list[mod] ans ans +  list[mod] ans list[mod] list mod n = n /26 n n /26 n 26 StringBuilder sb = new StringBuilder(ans); sb new StringBuilder(ans) String s = sb.reverse().toString(); s sb.reverse().toString() sb.reverse().toString sb.reverse() sb.reverse sb System.out.println(s) System.out.println System.out System System.out s String[] args args public class Main {    
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    }
} public class Main {    
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    }
} Main

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
 
public class Main {    
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        String[] list = new String[26];
        char temp = 'a';
        for(int i=0;i<26;i++){
            list[i] = String.valueOf(temp++);
        }

        String ans = "";
        while(0<n){
            n--;
            int mod = (int)( n % 26 );
            ans =ans +  list[mod];
            n = n /26;
        }
        StringBuilder sb = new StringBuilder(ans);
        String s = sb.reverse().toString();
        System.out.println(s);
    }
}