

import java.util.ArrayList;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	}


} import java.util.ArrayList; ArrayList java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	}


} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	} main {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long num = sc.nextLong(); num sc.nextLong() sc.nextLong sc ArrayList<Integer> numList = new ArrayList<Integer>(); numList new ArrayList<Integer>() while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		} true {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		} int digit = (int)(num % 26L); digit (int)(num % 26L) num 26L if (digit == 0) {
				digit = 26;
			} digit == 0 digit 0 {
				digit = 26;
			} digit = 26 digit 26 numList.add(digit + 96) numList.add numList digit + 96 digit 96 num = (num - digit) / 26L num (num - digit) / 26L (num - digit) num digit 26L if (num == 0) {
				break;
			} num == 0 num 0 {
				break;
			} break; for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		} int i = numList.size() - 1; int i = numList.size() - 1; i numList.size() - 1 numList.size() numList.size numList 1 i >= 0 i 0 i-- i-- i {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		} {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		} int let = (int)numList.get(i); let (int)numList.get(i) numList.get numList i char c = (char)let; c (char)let System.out.print(c) System.out.print System.out System System.out c String[] args args public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	}


} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	}


} Main


import java.util.ArrayList;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long num = sc.nextLong();
		ArrayList<Integer> numList = new ArrayList<Integer>();
		while (true) {
			int digit = (int)(num % 26L);
			if (digit == 0) {
				digit = 26;
			}
			numList.add(digit + 96);
			num = (num - digit) / 26L;
			if (num == 0) {
				break;
			}
		}

		for (int i = numList.size() - 1; i >= 0; i--) {
			int let = (int)numList.get(i);
			char c = (char)let;
			System.out.print(c);
		}
	}


}
