import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Arrays;
import java.util.Collections;
import java.util.*;
class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long N = scan.nextLong();
    String[] alp = {"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"};
    long dec = 0;
    StringBuilder sb = new StringBuilder();
    while(N / 27 > 0){
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    }
    dec = N % 26;
    if (dec == 0) {
      dec = 26;
    }
    int d = (int)dec;
    sb.append(alp[d - 1]);
    StringBuffer str = new StringBuffer(sb);
    String Name = str.reverse().toString();
    System.out.println(Name);
  }
}
 import java.util.Scanner; Scanner java.util import java.util.List; List java.util import java.util.ArrayList; ArrayList java.util import java.util.Comparator; Comparator java.util import java.util.Arrays; Arrays java.util import java.util.Collections; Collections java.util import java.util.*; util.* java class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long N = scan.nextLong();
    String[] alp = {"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"};
    long dec = 0;
    StringBuilder sb = new StringBuilder();
    while(N / 27 > 0){
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    }
    dec = N % 26;
    if (dec == 0) {
      dec = 26;
    }
    int d = (int)dec;
    sb.append(alp[d - 1]);
    StringBuffer str = new StringBuffer(sb);
    String Name = str.reverse().toString();
    System.out.println(Name);
  }
} Main public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long N = scan.nextLong();
    String[] alp = {"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"};
    long dec = 0;
    StringBuilder sb = new StringBuilder();
    while(N / 27 > 0){
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    }
    dec = N % 26;
    if (dec == 0) {
      dec = 26;
    }
    int d = (int)dec;
    sb.append(alp[d - 1]);
    StringBuffer str = new StringBuffer(sb);
    String Name = str.reverse().toString();
    System.out.println(Name);
  } main {
    Scanner scan = new Scanner(System.in);
    long N = scan.nextLong();
    String[] alp = {"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"};
    long dec = 0;
    StringBuilder sb = new StringBuilder();
    while(N / 27 > 0){
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    }
    dec = N % 26;
    if (dec == 0) {
      dec = 26;
    }
    int d = (int)dec;
    sb.append(alp[d - 1]);
    StringBuffer str = new StringBuffer(sb);
    String Name = str.reverse().toString();
    System.out.println(Name);
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long N = scan.nextLong(); N scan.nextLong() scan.nextLong scan String[] alp = {"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"}; alp {"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"} "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" long dec = 0; dec 0 StringBuilder sb = new StringBuilder(); sb new StringBuilder() while(N / 27 > 0){
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    } N / 27 > 0 N / 27 N 27 0 {
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    } dec = N % 26 dec N % 26 N 26 if (dec == 0) {
        dec = 26;
        N = N - 1;
      } dec == 0 dec 0 {
        dec = 26;
        N = N - 1;
      } dec = 26 dec 26 N = N - 1 N N - 1 N 1 int d = (int)dec; d (int)dec sb.append(alp[d - 1]) sb.append sb alp[d - 1] alp d - 1 d 1 N = N / 26 N N / 26 N 26 dec = N % 26 dec N % 26 N 26 if (dec == 0) {
      dec = 26;
    } dec == 0 dec 0 {
      dec = 26;
    } dec = 26 dec 26 int d = (int)dec; d (int)dec sb.append(alp[d - 1]) sb.append sb alp[d - 1] alp d - 1 d 1 StringBuffer str = new StringBuffer(sb); str new StringBuffer(sb) String Name = str.reverse().toString(); Name str.reverse().toString() str.reverse().toString str.reverse() str.reverse str System.out.println(Name) System.out.println System.out System System.out Name String[] args args
import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Arrays;
import java.util.Collections;
import java.util.*;
class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long N = scan.nextLong();
    String[] alp = {"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"};
    long dec = 0;
    StringBuilder sb = new StringBuilder();
    while(N / 27 > 0){
      dec = N % 26;
      if (dec == 0) {
        dec = 26;
        N = N - 1;
      }
      int d = (int)dec;
      sb.append(alp[d - 1]);
      N = N / 26;  
    }
    dec = N % 26;
    if (dec == 0) {
      dec = 26;
    }
    int d = (int)dec;
    sb.append(alp[d - 1]);
    StringBuffer str = new StringBuffer(sb);
    String Name = str.reverse().toString();
    System.out.println(Name);
  }
}

