import java.util.*;
import java.lang.Math;
public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    }
} import java.util.*; util.* java import java.lang.Math; Math java.lang public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long N = sc.nextLong(); N sc.nextLong() sc.nextLong sc int amari = 0; amari 0 String ans = ""; ans "" long kari = 0; kari 0 List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"); list Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z") Arrays.asList Arrays "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z" while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        } 0 < N 0 N {
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        } kari = N % 26 kari N % 26 N 26 if(kari == 0){
                kari = 26;
                N -= 1;
            } kari == 0 kari 0 {
                kari = 26;
                N -= 1;
            } kari = 26 kari 26 N -= 1 N 1 N /= 26 N 26 amari = (int)kari amari (int)kari ans += list.get(amari - 1) ans list.get(amari - 1) list.get list amari - 1 amari 1 StringBuffer sb = new StringBuffer(ans); sb new StringBuffer(ans) String dst = sb.reverse().toString(); dst sb.reverse().toString() sb.reverse().toString sb.reverse() sb.reverse sb System.out.println(dst) System.out.println System.out System System.out dst String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    }
} Main
import java.util.*;
import java.lang.Math;
public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        int amari = 0;
        String ans = "";
        long kari = 0;
        //System.out.println(N);
        List<String> list = Arrays.asList("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
        while(0 < N){
            kari = N % 26;
            if(kari == 0){
                kari = 26;
                N -= 1;
            }
            N /= 26;
            //System.out.println(kari);
           amari = (int)kari;
           ans += list.get(amari - 1);
        }
        StringBuffer sb = new StringBuffer(ans);
		String dst = sb.reverse().toString();
        System.out.println(dst);
    }
}
