
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Long n = sc.nextLong();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Long n = sc.nextLong();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Long n = sc.nextLong();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	} main {
		Scanner sc = new Scanner(System.in);
		Long n = sc.nextLong();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) Long n = sc.nextLong(); n sc.nextLong() sc.nextLong sc char[] s = new char[26]; s new char[26] 26 for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		} int i = 0; int i = 0; i 0 i < 26 i 26 i++ i++ i {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		} {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		} s[i] = (char) ('a' + i) s[i] s i (char) ('a' + i) 'a' i StringBuilder q =new StringBuilder(); q new StringBuilder() while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		} n > 0 n 0 {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		} long k = n % 26; k n % 26 n 26 if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			} k != 0 k 0 {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} int y = (int) k; y (int) k q.append(s[y - 1]) q.append q s[y - 1] s y - 1 y 1 n = n / 26 n n / 26 n 26 {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			} q.append(s[25]) q.append q s[25] s 25 n = n / 26 n n / 26 n 26 n = n - 1 n n - 1 n 1 q.reverse() q.reverse q System.out.println(q) System.out.println System.out System System.out q 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();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Long n = sc.nextLong();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	}
} Main

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Long n = sc.nextLong();
		char[] s = new char[26];

		for (int i = 0; i < 26; i++) {
			s[i] = (char) ('a' + i);
			// System.out.print(i+1+" ");
			// System.out.println((char) ('a'+i));
		}

		//ArrayList<Character> q = new ArrayList<>();
		StringBuilder q =new StringBuilder();

		while (n > 0) {
			long k = n % 26;
			//System.out.println(k);

			if (k != 0) {
				int y = (int) k;
				q.append(s[y - 1]);

				n = n / 26;

			} else {
				q.append(s[25]);
				n = n / 26;
				n = n - 1;
			}
		}

		q.reverse();
		System.out.println(q);
		sc.close();
	}
}
