import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    }
} import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.List; List 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();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    } main {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc long b = 0; b 0 List<Character> list = new ArrayList<>(); list new ArrayList<>() while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        } n > 0 n 0 {
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        } n-- n b = n % 26 b n % 26 n 26 list.add((char)('a' + b)) list.add list (char)('a' + b) 'a' b n /= 26 n 26 Collections.reverse(list) Collections.reverse Collections list for(char c : list) {
            System.out.print(c);
        } char c list {
            System.out.print(c);
        } {
            System.out.print(c);
        } System.out.print(c) System.out.print System.out System System.out c String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    }
} Main
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long b = 0;
        List<Character> list = new ArrayList<>();
        while (n > 0){
            n--;
            b = n % 26;
            list.add((char)('a' + b));
            n /= 26;
        }
        Collections.reverse(list);
        for(char c : list) {
            System.out.print(c);
        }
    }
}