import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    }
} import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    } main {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long N = Long.parseLong(sc.next()); N Long.parseLong(sc.next()) Long.parseLong Long sc.next() sc.next sc String name = ""; name "" long n = 0; n 0 String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" }; alphabet { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" } "z" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        } 0 < N 0 N {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        } n = N % 26 n N % 26 N 26 name = alphabet[(int) (n)] + name name alphabet[(int) (n)] + name alphabet[(int) (n)] alphabet (int) (n) name N = N / 26 N N / 26 N 26 if (n == 0) {
                N -= 1;
            } n == 0 n 0 {
                N -= 1;
            } N -= 1 N 1 PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) out.println(name) out.println out name sc.close() sc.close sc out.flush() out.flush out String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    }
} Main
import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = Long.parseLong(sc.next());
        String name = "";
        long n = 0;
        String[] alphabet = { "z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q",
                "r", "s", "t", "u", "v", "w", "x", "y" };

        while (0 < N) {
            n = N % 26;
            name = alphabet[(int) (n)] + name;
            N = N / 26;
            if (n == 0) {
                N -= 1;
            }
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(name);

        sc.close();
        out.flush();
    }
}