import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    }
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    }
} Main public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    } main {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    } BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in)); buffer new BufferedReader(new InputStreamReader(System.in)) StringBuilder sb = new StringBuilder(); sb new StringBuilder() long n = Long.parseLong(buffer.readLine()); n Long.parseLong(buffer.readLine()) Long.parseLong Long buffer.readLine() buffer.readLine buffer String name = ""; name "" while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        } n != 0 n 0 {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        } n-- n name += (char)('a'+ (n%26)) name (char)('a'+ (n%26)) 'a' (n%26) n 26 n /= 26 n 26 sb.append(name) sb.append sb name sb = sb.reverse() sb sb.reverse() sb.reverse sb sb.append("\n") sb.append sb "\n" System.out.println(sb) System.out.println System.out System System.out sb String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    }
} Main
import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        long n = Long.parseLong(buffer.readLine());
        String name = "";
        while (n != 0)
        {
            n--;
            name += (char)('a'+ (n%26));
            n /= 26;
        }
        sb.append(name);
        sb = sb.reverse();
        sb.append("\n");
        System.out.println(sb);
    }
}
