/*package whatever //do not write package name here */
import java.util.*;
import java.lang.*;
import java.io.*;

class Main {
	public static void main (String[] args) {
// 		System.out.println("GfG!");
        Scanner input=new Scanner(System.in);
       char[] array=new char[26];
       array[0]='z';
       for(int i=1;i<26;i++)
            array[i]=(char)(i+96);
        /*for(int i=0;i<26;i++)
            System.out.print(array[i] + " ");*/
        long n=input.nextLong();
        List<Integer> list=new ArrayList<Integer>();
        while(n>0)
        {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        }
        // System.out.println(list);
        int size=list.size();
        for(int i=size-1;i>=0;i--)
        {
            int x=list.get(i);
            System.out.print(array[x]);
        }
       input.close();
	}
} import java.util.*; util.* java import java.lang.*; lang.* java import java.io.*; io.* java class Main {
	public static void main (String[] args) {
// 		System.out.println("GfG!");
        Scanner input=new Scanner(System.in);
       char[] array=new char[26];
       array[0]='z';
       for(int i=1;i<26;i++)
            array[i]=(char)(i+96);
        /*for(int i=0;i<26;i++)
            System.out.print(array[i] + " ");*/
        long n=input.nextLong();
        List<Integer> list=new ArrayList<Integer>();
        while(n>0)
        {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        }
        // System.out.println(list);
        int size=list.size();
        for(int i=size-1;i>=0;i--)
        {
            int x=list.get(i);
            System.out.print(array[x]);
        }
       input.close();
	}
} Main public static void main (String[] args) {
// 		System.out.println("GfG!");
        Scanner input=new Scanner(System.in);
       char[] array=new char[26];
       array[0]='z';
       for(int i=1;i<26;i++)
            array[i]=(char)(i+96);
        /*for(int i=0;i<26;i++)
            System.out.print(array[i] + " ");*/
        long n=input.nextLong();
        List<Integer> list=new ArrayList<Integer>();
        while(n>0)
        {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        }
        // System.out.println(list);
        int size=list.size();
        for(int i=size-1;i>=0;i--)
        {
            int x=list.get(i);
            System.out.print(array[x]);
        }
       input.close();
	} main {
// 		System.out.println("GfG!");
        Scanner input=new Scanner(System.in);
       char[] array=new char[26];
       array[0]='z';
       for(int i=1;i<26;i++)
            array[i]=(char)(i+96);
        /*for(int i=0;i<26;i++)
            System.out.print(array[i] + " ");*/
        long n=input.nextLong();
        List<Integer> list=new ArrayList<Integer>();
        while(n>0)
        {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        }
        // System.out.println(list);
        int size=list.size();
        for(int i=size-1;i>=0;i--)
        {
            int x=list.get(i);
            System.out.print(array[x]);
        }
       input.close();
	} Scanner input=new Scanner(System.in); input new Scanner(System.in) char[] array=new char[26]; array new char[26] 26 array[0]='z' array[0] array 0 'z' for(int i=1;i<26;i++)
            array[i]=(char)(i+96); int i=1; int i=1; i 1 i<26 i 26 i++ i++ i array[i]=(char)(i+96); array[i]=(char)(i+96) array[i] array i (char)(i+96) i 96 long n=input.nextLong(); n input.nextLong() input.nextLong input List<Integer> list=new ArrayList<Integer>(); list new ArrayList<Integer>() while(n>0)
        {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        } n>0 n 0 {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        } long x=n%26; x n%26 n 26 list.add((int)x) list.add list (int)x if(x==0)
                n=n-26; x==0 x 0 n=n-26 n n-26 n 26 n=n/26 n n/26 n 26 int size=list.size(); size list.size() list.size list for(int i=size-1;i>=0;i--)
        {
            int x=list.get(i);
            System.out.print(array[x]);
        } int i=size-1; int i=size-1; i size-1 size 1 i>=0 i 0 i-- i-- i {
            int x=list.get(i);
            System.out.print(array[x]);
        } {
            int x=list.get(i);
            System.out.print(array[x]);
        } int x=list.get(i); x list.get(i) list.get list i System.out.print(array[x]) System.out.print System.out System System.out array[x] array x input.close() input.close input String[] args args
/*package whatever //do not write package name here */
import java.util.*;
import java.lang.*;
import java.io.*;

class Main {
	public static void main (String[] args) {
// 		System.out.println("GfG!");
        Scanner input=new Scanner(System.in);
       char[] array=new char[26];
       array[0]='z';
       for(int i=1;i<26;i++)
            array[i]=(char)(i+96);
        /*for(int i=0;i<26;i++)
            System.out.print(array[i] + " ");*/
        long n=input.nextLong();
        List<Integer> list=new ArrayList<Integer>();
        while(n>0)
        {
            long x=n%26;
            list.add((int)x);
            if(x==0)
                n=n-26;
            n=n/26;
        }
        // System.out.println(list);
        int size=list.size();
        for(int i=size-1;i>=0;i--)
        {
            int x=list.get(i);
            System.out.print(array[x]);
        }
       input.close();
	}
}