import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    }

    private static String read(long num) {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    }

} import java.util.*; util.* java public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    }

    private static String read(long num) {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    }

} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    } main {
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long num = sc.nextLong(); num sc.nextLong() sc.nextLong sc System.out.print(read(num)) System.out.print System.out System System.out read(num) read num String[] args args private static String read(long num) {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    } read {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    } if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        } num<=26 num 26 {
            char c = (char)(num+96);
            return String.valueOf(c);
        } char c = (char)(num+96); c (char)(num+96) num 96 return String.valueOf(c); String.valueOf(c) String.valueOf String c {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        } long b = num%26; b num%26 num 26 char c = (char)(b+96); c (char)(b+96) b 96 num = num/26 num num/26 num 26 if (b==0) {
                num -= 1;
                c = 'z';
            } b==0 b 0 {
                num -= 1;
                c = 'z';
            } num -= 1 num 1 c = 'z' c 'z' return read(num) + c; read(num) + c read(num) read num c long num num public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    }

    private static String read(long num) {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    }

} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    }

    private static String read(long num) {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    }

} Main
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long num = sc.nextLong();
        System.out.print(read(num));
    }

    private static String read(long num) {
        if(num<=26) {
            char c = (char)(num+96);
            return String.valueOf(c);
        } else {
            long b = num%26;
            char c = (char)(b+96);
            num = num/26;

            if (b==0) {
                num -= 1;
                c = 'z';
            }
            return read(num) + c;
        }
    }

}