import java.util.Scanner;

public class Main {
    public static void main(String args[]) {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

        System.out.println(name.reverse().toString());
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String args[]) {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

        System.out.println(name.reverse().toString());
    }
} Main public static void main(String args[]) {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

        System.out.println(name.reverse().toString());
    } main {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

        System.out.println(name.reverse().toString());
    } char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray(); alphabet "abcdefghijklmnopqrstuvwxyz".toCharArray() "abcdefghijklmnopqrstuvwxyz".toCharArray "abcdefghijklmnopqrstuvwxyz" Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long n = scan.nextLong(); n scan.nextLong() scan.nextLong scan StringBuilder name = new StringBuilder(); name new StringBuilder() int surplus; surplus for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        } ; n > 0 n 0 n = (n - 1) / 26 n = (n - 1) / 26 n (n - 1) / 26 (n - 1) n 1 26 {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        } {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        } surplus = (int) ((n - 1) % 26) surplus (int) ((n - 1) % 26) (n - 1) n 1 26 name.append(alphabet[surplus]) name.append name alphabet[surplus] alphabet surplus System.out.println(name.reverse().toString()) System.out.println System.out System System.out name.reverse().toString() name.reverse().toString name.reverse() name.reverse name String args[] args public class Main {
    public static void main(String args[]) {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

        System.out.println(name.reverse().toString());
    }
} public class Main {
    public static void main(String args[]) {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

        System.out.println(name.reverse().toString());
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String args[]) {
        char[] alphabet = "abcdefghijklmnopqrstuvwxyz".toCharArray();

        Scanner scan = new Scanner(System.in);

        long n = scan.nextLong();

        StringBuilder name = new StringBuilder();
        int surplus;
        for (; n > 0; n = (n - 1) / 26) {
            surplus = (int) ((n - 1) % 26);
            name.append(alphabet[surplus]);
        }

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