import java.util.Scanner;
/**
 * 解题方法 26 进制
 * k 进制每一位最大只有 k - 1，但是此道题目最大可以是 26，所以每次处理 N - 1
 */
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    } main {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) long N = scanner.nextLong(); N scanner.nextLong() scanner.nextLong scanner String ans = ""; ans "" while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        } N > 0 N 0 {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        } N-- N ans = (char)(N % 26 + 97) + ans ans (char)(N % 26 + 97) + ans (char)(N % 26 + 97) N % 26 N 26 97 ans N /= 26 N 26 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    }
} Main
import java.util.Scanner;
/**
 * 解题方法 26 进制
 * k 进制每一位最大只有 k - 1，但是此道题目最大可以是 26，所以每次处理 N - 1
 */
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        long N = scanner.nextLong();
        String ans = "";
        while (N > 0) {
            N--;
            ans = (char)(N % 26 + 97) + ans;
            N /= 26;
        }
        System.out.println(ans);
    }
}