    import java.util.Scanner;
     
    public class Main {
        public static void main(String args[]) {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        }
    }
 import java.util.Scanner; Scanner java.util public class Main {
        public static void main(String args[]) {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        }
    } Main public static void main(String args[]) {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        } main {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        } char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray(); ch "abcdefghijklmnopqrstuvwxyz".toCharArray() "abcdefghijklmnopqrstuvwxyz".toCharArray "abcdefghijklmnopqrstuvwxyz" Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long n = scan.nextLong(); n scan.nextLong() scan.nextLong scan StringBuilder sb = new StringBuilder(); sb new StringBuilder() int t; t for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            } ; n > 0 n 0 n = (n - 1) / 26 n = (n - 1) / 26 n (n - 1) / 26 (n - 1) n 1 26 {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            } {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            } t = (int) ((n - 1) % 26) t (int) ((n - 1) % 26) (n - 1) n 1 26 sb.append(ch[t]) sb.append sb ch[t] ch t System.out.println(sb.reverse().toString()) System.out.println System.out System System.out sb.reverse().toString() sb.reverse().toString sb.reverse() sb.reverse sb String args[] args public class Main {
        public static void main(String args[]) {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        }
    } public class Main {
        public static void main(String args[]) {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        }
    } Main
    import java.util.Scanner;
     
    public class Main {
        public static void main(String args[]) {
            char[] ch = "abcdefghijklmnopqrstuvwxyz".toCharArray();
     
            Scanner scan = new Scanner(System.in);
     
            long n = scan.nextLong();
     
            StringBuilder sb = new StringBuilder();
            int t;
            for (; n > 0; n = (n - 1) / 26) {
                t = (int) ((n - 1) % 26);
                sb.append(ch[t]);
            }
     
            System.out.println(sb.reverse().toString());
        }
    }

