import java.util.*;
public class Main{
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  }
} Main public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  } main {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) long n=sc.nextLong(); n sc.nextLong() sc.nextLong sc String s="abcdefghijklmnopqrstuvwxyz"; s "abcdefghijklmnopqrstuvwxyz" char[] c=s.toCharArray(); c s.toCharArray() s.toCharArray s StringBuilder s1=new StringBuilder(); s1 new StringBuilder() while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     } n>0 n 0 {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     } long x=Math.abs(n%26); x Math.abs(n%26) Math.abs Math n%26 n 26 if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      } x!=0 x 0 {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       } int y=(int)x; y (int)x s1.append(c[y-1]) s1.append s1 c[y-1] c y-1 y 1 n=n/26 n n/26 n 26 {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      } s1.append(c[25]) s1.append s1 c[25] c 25 n=n/26 n n/26 n 26 n=n-1 n n-1 n 1 s1.reverse() s1.reverse s1 System.out.println(s1) System.out.println System.out System System.out s1 String[] args args public class Main{
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  }
} public class Main{
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  }
} Main
import java.util.*;
public class Main{
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
long n=sc.nextLong();
     String s="abcdefghijklmnopqrstuvwxyz";
     char[] c=s.toCharArray();
   StringBuilder s1=new StringBuilder();
     while(n>0)
     {
    	
       long x=Math.abs(n%26);
  
       if(x!=0)
       {
    	   int y=(int)x;
           s1.append(c[y-1]);
         
         n=n/26;
        
       }
       else
      {
         s1.append(c[25]);
          n=n/26;
	 n=n-1;
      }
       
      
     }
 s1.reverse();
   System.out.println(s1);
  }
}