import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    } main {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long n = Long.parseLong(sc.next()); n Long.parseLong(sc.next()) Long.parseLong Long sc.next() sc.next sc int k = 26; k 26 StringBuilder ans = new StringBuilder(); ans new StringBuilder() while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        } n != 0 n 0 {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        } char a = (char)(n % k + 96); a (char)(n % k + 96) n % k n k 96 if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            } n % k == 0 n % k n k 0 {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            } a = 'z' a 'z' ans.insert(0, a) ans.insert ans 0 a n /= k n k n-- n {
                ans.insert(0, a);  
                n /= k;
            } ans.insert(0, a) ans.insert ans 0 a n /= k n k System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        long n = Long.parseLong(sc.next());
        int k = 26;
        StringBuilder ans = new StringBuilder();
        while(n != 0) {
            char a = (char)(n % k + 96);
            if(n % k == 0) {
                a = 'z';
                ans.insert(0, a); 
                n /= k;
                n--;
            }else {
                ans.insert(0, a);  
                n /= k;
            }
        }
        System.out.println(ans);
    }
}
