
import java.util.Map.Entry;
import java.util.*;
import java.math.*;
import org.w3c.dom.css.Counter;
  
public class Main{
    public static void main(final String[] args){
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    }
}
    


     ArrayList <String>(){{}} import java.util.Map.Entry; Entry java.util.Map import java.util.*; util.* java import java.math.*; math.* java import org.w3c.dom.css.Counter; Counter org.w3c.dom.css public class Main{
    public static void main(final String[] args){
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    }
} Main public static void main(final String[] args){
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    } main {
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    } final Scanner sc = new Scanner(System.in); sc new Scanner(System.in) ArrayList<String>  allmen =new ArrayList <String>(){{}}; allmen new ArrayList <String>(){{}} String abc = "abcdefghijklmnopqrstuvwxyz"; abc "abcdefghijklmnopqrstuvwxyz" int bigNum =11; bigNum 11 Long alf = 26l; alf 26l Long N = sc.nextLong(); N sc.nextLong() sc.nextLong sc String ans = ""; ans "" for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        } int i=bigNum; int i=bigNum; i bigNum N>0 N 0 i-- i-- i {
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        } {
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        } Long targetNum = N-1; targetNum N-1 N 1 int targetStr = (int)(targetNum%alf); targetStr (int)(targetNum%alf) targetNum alf ans = abc.substring(targetStr,targetStr+1)+ans ans abc.substring(targetStr,targetStr+1)+ans abc.substring(targetStr,targetStr+1) abc.substring abc targetStr targetStr+1 targetStr 1 ans N =  targetNum/alf N targetNum/alf targetNum alf System.out.println(ans) System.out.println System.out System System.out ans final String[] args args public class Main{
    public static void main(final String[] args){
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    }
} public class Main{
    public static void main(final String[] args){
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    }
} Main

import java.util.Map.Entry;
import java.util.*;
import java.math.*;
import org.w3c.dom.css.Counter;
  
public class Main{
    public static void main(final String[] args){
       
        final Scanner sc = new Scanner(System.in);

        ArrayList<String>  allmen =new ArrayList <String>(){{}};
        String abc = "abcdefghijklmnopqrstuvwxyz";
        int bigNum =11;
        Long alf = 26l;
        Long N = sc.nextLong();
        String ans = "";
        
        for(int i=bigNum;N>0;i--){
            Long targetNum = N-1;
            int targetStr = (int)(targetNum%alf);
            ans = abc.substring(targetStr,targetStr+1)+ans;
            N =  targetNum/alf;
        }


        System.out.println(ans);

    }
}
    


    