
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    }

} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    }

} Main public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    } main {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long n = Long.parseLong(scan.next()); n Long.parseLong(scan.next()) Long.parseLong Long scan.next() scan.next scan scan.close() scan.close scan StringBuilder sb = new StringBuilder(); sb new StringBuilder() while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        } n > 0 n 0 {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        } long l = n % 26; l n % 26 n 26 if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            } l == 0 l 0 {
                sb.append('z');
                n -= 1;
            } sb.append('z') sb.append sb 'z' n -= 1 n 1 {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            } char c = 'a'; c 'a' c += l - 1 c l - 1 l 1 sb.append(c) sb.append sb c n /= 26 n 26 System.out.println(sb.reverse().toString()) System.out.println System.out System System.out sb.reverse().toString() sb.reverse().toString sb.reverse() sb.reverse sb String[] args args public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    }

} public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    }

} Main

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        long n = Long.parseLong(scan.next());
        scan.close();

        StringBuilder sb = new StringBuilder();

        while (n > 0) {
            long l = n % 26;
            if (l == 0) {
                sb.append('z');
                n -= 1;
            } else {
                char c = 'a';
                c += l - 1;
                sb.append(c);
            }

            n /= 26;
        }

        System.out.println(sb.reverse().toString());
    }

}
