
import java.io.*;
public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    }
} import java.io.*; io.* java public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    }
} Main public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    } main {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); bw new BufferedWriter(new OutputStreamWriter(System.out)) long number = Long.parseLong(br.readLine()); number Long.parseLong(br.readLine()) Long.parseLong Long br.readLine() br.readLine br long temp = 0; temp 0 long cnt = 1; cnt 1 String name = ""; name "" while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        } true {
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        } temp = number temp number number -= Math.pow(26, cnt) number Math.pow(26, cnt) Math.pow Math 26 cnt if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            } number <= 0 number 0 {

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            } number = temp-1 number temp-1 temp 1 cnt-- cnt if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                } cnt == 0 cnt 0 {
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                } long alphabat = number%26; alphabat number%26 number 26 char part = (char) (alphabat+97); part (char) (alphabat+97) alphabat 97 name += part name part break; while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                } cnt > 0 cnt 0 {


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                } long tempNum = (long)Math.pow(26, cnt); tempNum (long)Math.pow(26, cnt) Math.pow Math 26 cnt long alphabat = number/tempNum; alphabat number/tempNum number tempNum char part = (char) (alphabat+97); part (char) (alphabat+97) alphabat 97 number -= (tempNum)*alphabat number (tempNum)*alphabat (tempNum) alphabat name += part name part if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    } cnt ==1 cnt 1 {
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    } alphabat = number%26 alphabat number%26 number 26 part = (char) (alphabat+97) part (char) (alphabat+97) alphabat 97 name += part name part cnt-- cnt break; cnt++ cnt System.out.println(name) System.out.println System.out System System.out name String[] args args public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    }
} public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    }
} Main

import java.io.*;
public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        long number = Long.parseLong(br.readLine());
        long temp = 0;
        long cnt = 1;
        String name = "";
        while(true){
            temp = number;
            number -= Math.pow(26, cnt);

            if(number <= 0){

                number = temp-1;
                cnt--;

                if(cnt == 0){
                    long alphabat = number%26;
                    char part = (char) (alphabat+97);
                    name += part;
                    break;
                }

                while(cnt > 0){


                    long tempNum = (long)Math.pow(26, cnt);
                    long alphabat = number/tempNum; // 0이라면 그냥 a
                    char part = (char) (alphabat+97);
                    number -= (tempNum)*alphabat;


                    name += part;

                    if(cnt ==1){
                        alphabat = number%26;
                        part = (char) (alphabat+97);
                        name += part;
                    }

                    cnt--;
                }

                break;
            }
            cnt++;
        }
        System.out.println(name);
    }
}
