import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    }
} import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) Long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc StringBuilder sb = new StringBuilder(); sb new StringBuilder() while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
} n-->0 n-- n 0 {
    sb.append((char)('a'+n%26));
    n/=26;
} sb.append((char)('a'+n%26)) sb.append sb (char)('a'+n%26) 'a' n%26 n 26 n/=26 n 26 sb.reverse() sb.reverse sb System.out.println(sb.toString()) System.out.println System.out System System.out sb.toString() sb.toString sb sc.close() sc.close sc String[] args args public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    }
} public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    }
} Main
import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Long n = sc.nextLong();
StringBuilder sb = new StringBuilder();

while(n-->0){
    sb.append((char)('a'+n%26));
    n/=26;
}sb.reverse();
System.out.println(sb.toString());

        sc.close();
    }
}