import java.util.Scanner;

public class Main {

    public static final int MOD = 1000000007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    }
} import java.util.Scanner; Scanner java.util public class Main {

    public static final int MOD = 1000000007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    }
} Main public static final int MOD = 1000000007; MOD 1000000007 public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    } main {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    } 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 s = Long.toString(n, 26); s Long.toString(n, 26) Long.toString Long n 26 StringBuilder sb = new StringBuilder(); sb new StringBuilder() int len = s.length(); len s.length() s.length s int idx = 0; idx 0 if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        } n <= 26 n 26 {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } s = Long.toString(n - 1, 26) s Long.toString(n - 1, 26) Long.toString Long n - 1 n 1 26 int num = Integer.parseInt(s, 26); num Integer.parseInt(s, 26) Integer.parseInt Integer s 26 sb.append((char) ('a' + num)) sb.append sb (char) ('a' + num) 'a' num {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        } while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            } s.length() >= 1 s.length() s.length s 1 {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            } if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                } s.substring(s.length() - 1).equals("0") s.substring(s.length() - 1).equals s.substring(s.length() - 1) s.substring s s.length() - 1 s.length() s.length s 1 "0" {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } long dec = Long.parseLong(s, 26) - 1; dec Long.parseLong(s, 26) - 1 Long.parseLong(s, 26) Long.parseLong Long s 26 1 String ss = Long.toString(dec, 26); ss Long.toString(dec, 26) Long.toString Long dec 26 int num = Integer.parseInt(ss.substring(ss.length() - 1), 26); num Integer.parseInt(ss.substring(ss.length() - 1), 26) Integer.parseInt Integer ss.substring(ss.length() - 1) ss.substring ss ss.length() - 1 ss.length() ss.length ss 1 26 sb.append((char) ('a' + num)) sb.append sb (char) ('a' + num) 'a' num s = ss s ss idx++ idx {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                } int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1; num Integer.parseInt(s.substring(s.length() - 1), 26) - 1 Integer.parseInt(s.substring(s.length() - 1), 26) Integer.parseInt Integer s.substring(s.length() - 1) s.substring s s.length() - 1 s.length() s.length s 1 26 1 sb.append((char) ('a' + num)) sb.append sb (char) ('a' + num) 'a' num s = s.substring(0, s.length() - 1) s s.substring(0, s.length() - 1) s.substring s 0 s.length() - 1 s.length() s.length s 1 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 final int MOD = 1000000007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    }
} public class Main {

    public static final int MOD = 1000000007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    }
} Main
import java.util.Scanner;

public class Main {

    public static final int MOD = 1000000007;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        String s = Long.toString(n, 26);
        StringBuilder sb = new StringBuilder();
        int len = s.length();
        int idx = 0;
        if (n <= 26) {
            s = Long.toString(n - 1, 26);
            int num = Integer.parseInt(s, 26);
            sb.append((char) ('a' + num));
        } else {
            while (s.length() >= 1) {
                if (s.substring(s.length() - 1).equals("0")) {
                    long dec = Long.parseLong(s, 26) - 1;
                    String ss = Long.toString(dec, 26);
                    int num = Integer.parseInt(ss.substring(ss.length() - 1), 26);
                    sb.append((char) ('a' + num));
                    s = ss;
                    idx++;
                } else {
                    int num = Integer.parseInt(s.substring(s.length() - 1), 26) - 1;
                    sb.append((char) ('a' + num));
                }
                s = s.substring(0, s.length() - 1);
            }
        }
        System.out.println(sb.reverse().toString());
    }
}