import java.math.BigDecimal;
import java.util.Scanner;

/**
 * @author : Ritchie Zhang
 * @date : 2020/5/10
 * @description： TODO
 * @modifiedBy：
 * @version: 1.0
 */
public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    }

    public static String change(long n){
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    }
}

 import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    }

    public static String change(long n){
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    }
} Main public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    } main {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    } Scanner s = new Scanner(System.in); s new Scanner(System.in) long a = s.nextLong(); a s.nextLong() s.nextLong s System.out.println(change(a)) System.out.println System.out System System.out change(a) change a String[] args args public static String change(long n){
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    } change {
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    } String s = ""; s "" while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        } n>0 n 0 {
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        } long m = n % 26; m n % 26 n 26 if (m == 0)
            {
                m = 26;
            } m == 0 m 0 {
                m = 26;
            } m = 26 m 26 s = (char)(m + 96) + s s (char)(m + 96) + s (char)(m + 96) m 96 s n = (n - m) / 26 n (n - m) / 26 (n - m) n m 26 return s; s long n n public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    }

    public static String change(long n){
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    }
} public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    }

    public static String change(long n){
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    }
} Main
import java.math.BigDecimal;
import java.util.Scanner;

/**
 * @author : Ritchie Zhang
 * @date : 2020/5/10
 * @description： TODO
 * @modifiedBy：
 * @version: 1.0
 */
public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long a = s.nextLong();
        System.out.println(change(a));


    }

    public static String change(long n){
        String s = "";
        while (n>0){
            long m = n % 26;
            if (m == 0)
            {
                m = 26;
            }
            s = (char)(m + 96) + s;
            n = (n - m) / 26;
        }
        return s;
    }
}


