import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc long x = n; x n String res = ""; res "" while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        } x != 0 x 0 {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        } int r = (int)(x % 26); r (int)(x % 26) x 26 if (r == 0) {
                r = 26;
            } r == 0 r 0 {
                r = 26;
            } r = 26 r 26 char c = (char)(96 + r); c (char)(96 + r) 96 r res += String.valueOf(c) res String.valueOf(c) String.valueOf String c x = (x - r) / 26 x (x - r) / 26 (x - r) x r 26 StringBuffer bufres = new StringBuffer(res); bufres new StringBuffer(res) String res1 = bufres.reverse().toString(); res1 bufres.reverse().toString() bufres.reverse().toString bufres.reverse() bufres.reverse bufres System.out.println(res1) System.out.println System.out System System.out res1 sc.close() sc.close sc String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long x = n;
        String res = "";
        while (x != 0) {
            int r = (int)(x % 26);
            if (r == 0) {
                r = 26;
            }
            char c = (char)(96 + r);
            res += String.valueOf(c);
            x = (x - r) / 26;
        }
        StringBuffer bufres = new StringBuffer(res);
        String res1 = bufres.reverse().toString();
        System.out.println(res1);
        sc.close();
    }
}