
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    }
} import java.util.Arrays; Arrays java.util 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[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    } main {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc long[] pow26 = new long[14]; pow26 new long[14] 14 for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        } int i=1; int i=1; i 1 i<14 i 14 i++ i++ i {
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        } {
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        } pow26[i] = pow26[i-1] + (long) Math.pow(26, i) pow26[i] pow26 i pow26[i-1] + (long) Math.pow(26, i) pow26[i-1] pow26 i-1 i 1 (long) Math.pow(26, i) Math.pow Math 26 i int length = 0; length 0 for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        } int i=0; int i=0; i 0 i<14 i 14 i++ i++ i {
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        } {
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        } if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            } n > pow26[i] && n <= pow26[i+1] n > pow26[i] n pow26[i] pow26 i n <= pow26[i+1] n pow26[i+1] pow26 i+1 i 1 {
                length = i+1;
                break;
            } length = i+1 length i+1 i 1 break; int x = (int) (n % 26); x (int) (n % 26) n 26 x = x == 0 ? 26 : x x x == 0 ? 26 : x x == 0 x 0 26 x String s = String.valueOf((char)(x+96)); s String.valueOf((char)(x+96)) String.valueOf String (char)(x+96) x 96 n -= 26 n 26 for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        } int i=1; int i=1; i 1 i<length i length i++ i++ i {
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        } {
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        } long z = n % (long)Math.pow(26, i+1); z n % (long)Math.pow(26, i+1) n (long)Math.pow(26, i+1) Math.pow Math 26 i+1 i 1 z = z == 0 ? (long)Math.pow(26, i+1) : z z z == 0 ? (long)Math.pow(26, i+1) : z z == 0 z 0 (long)Math.pow(26, i+1) Math.pow Math 26 i+1 i 1 z int y = (int)((z-1) / (long)Math.pow(26, i)) + 1; y (int)((z-1) / (long)Math.pow(26, i)) + 1 (int)((z-1) / (long)Math.pow(26, i)) (z-1) z 1 (long)Math.pow(26, i) Math.pow Math 26 i 1 s = String.valueOf((char)(y+96)) + s s String.valueOf((char)(y+96)) + s String.valueOf((char)(y+96)) String.valueOf String (char)(y+96) y 96 s n -= (long)Math.pow(26, i+1) n (long)Math.pow(26, i+1) Math.pow Math 26 i+1 i 1 System.out.println(s) System.out.println System.out System System.out s String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    }
} Main

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long[] pow26 = new long[14];
        for(int i=1;i<14;i++){
            pow26[i] = pow26[i-1] + (long) Math.pow(26, i);
        }
        int length = 0;
        for(int i=0;i<14;i++){
            if(n > pow26[i] && n <= pow26[i+1]){
                length = i+1;
                break;
            }
        }
        //length=桁数
        int x = (int) (n % 26);
        x = x == 0 ? 26 : x;
        String s = String.valueOf((char)(x+96));
        n -= 26;
        for(int i=1;i<length;i++){
            long z = n % (long)Math.pow(26, i+1);
            z = z == 0 ? (long)Math.pow(26, i+1) : z;
            int y = (int)((z-1) / (long)Math.pow(26, i)) + 1;
            s = String.valueOf((char)(y+96)) + s;
            n -= (long)Math.pow(26, i+1);
        }
        System.out.println(s);

    }
}
