import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	}
} Main public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	} main {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) long number = scanner.nextLong(); number scanner.nextLong() scanner.nextLong scanner String result = new String(); result new String() while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		} number > 0 number 0 {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		} int nums = (int) ('a' + (number - 1) % 26); nums (int) ('a' + (number - 1) % 26) 'a' (number - 1) % 26 (number - 1) number 1 26 char temporal = (char) nums; temporal (char) nums result = temporal + result result temporal + result temporal result number = number / 26 number number / 26 number 26 if(temporal == 'z')
				number--; temporal == 'z' temporal 'z' number-- number System.out.print(result) System.out.print System.out System System.out result String[] args args public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long number = scanner.nextLong();
		String result = new String();
		
		while(number > 0) {
			int nums = (int) ('a' + (number - 1) % 26);
			char temporal = (char) nums;
			result = temporal + result;
			number = number / 26;
			if(temporal == 'z')
				number--;
		}
		System.out.print(result);
	}
}
