

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    }
} 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();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    } main {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long N = sc.nextLong(); N sc.nextLong() sc.nextLong sc String tmp = ""; tmp "" while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        } N>0 N 0 {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        } --N N tmp += (char)('a' + (N%26)) tmp (char)('a' + (N%26)) 'a' (N%26) N 26 N /= 26 N 26 StringBuffer sb = new StringBuffer(tmp); sb new StringBuffer(tmp) String res = sb.reverse().toString(); res sb.reverse().toString() sb.reverse().toString sb.reverse() sb.reverse sb System.out.println(res) System.out.println System.out System System.out res String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    }
} Main


import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        String tmp = "";

        while(N>0) {
            --N;
            tmp += (char)('a' + (N%26));
            N /= 26;
        }
        StringBuffer sb = new StringBuffer(tmp);
        String res = sb.reverse().toString();
        System.out.println(res);
    }
}
