import java.util.*;
import java.math.BigInteger;

public class Main{
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

}
}
 import java.util.*; util.* java import java.math.BigInteger; BigInteger java.math public class Main{
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

}
} Main public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

} main {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) BigInteger a = new BigInteger(scan.next()); a new BigInteger(scan.next()) scan.close() scan.close scan int[] alpha = new int[26]; alpha new int[26] 26 int cnt = 0; cnt 0 int tmp; tmp BigInteger bi26 = new BigInteger("26"); bi26 new BigInteger("26") BigInteger bi1 = new BigInteger("1"); bi1 new BigInteger("1") BigInteger bi0 = new BigInteger("0"); bi0 new BigInteger("0") while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    } a.compareTo(bi0) == 1 a.compareTo(bi0) a.compareTo a bi0 1 {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    } BigInteger rem = a.remainder(bi26); rem a.remainder(bi26) a.remainder a bi26 String strrem = rem.toString(); strrem rem.toString() rem.toString rem tmp = Integer.parseInt(strrem) tmp Integer.parseInt(strrem) Integer.parseInt Integer strrem if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        } tmp == 0 tmp 0 {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } alpha[cnt] = 26 alpha[cnt] alpha cnt 26 a = a.divide(bi26) a a.divide(bi26) a.divide a bi26 a = a.subtract(bi1) a a.subtract(bi1) a.subtract a bi1 {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        } alpha[cnt] = tmp alpha[cnt] alpha cnt tmp a = a.divide(bi26) a a.divide(bi26) a.divide a bi26 cnt++ cnt byte[] ascii = new byte[cnt]; ascii new byte[cnt] cnt for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    } int i=0; int i=0; i 0 i<cnt i cnt i++ i++ i {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    } {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    } ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1) ascii[cnt - i -1] ascii cnt - i -1 cnt - i -1 cnt i 1 (byte)(97 + alpha[i] - 1) 97 + alpha[i] 97 alpha[i] alpha i 1 String outstr = new String(ascii); outstr new String(ascii) System.out.println(outstr) System.out.println System.out System System.out outstr String[] args args public class Main{
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

}
} public class Main{
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

}
} Main
import java.util.*;
import java.math.BigInteger;

public class Main{
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    BigInteger a = new BigInteger(scan.next());
    scan.close();

    int[] alpha = new int[26];
    int cnt = 0;
    int tmp;
    BigInteger bi26 = new BigInteger("26");
    BigInteger bi1 = new BigInteger("1");
    BigInteger bi0 = new BigInteger("0");
    while(a.compareTo(bi0) == 1) {
        BigInteger rem = a.remainder(bi26);
        String strrem = rem.toString();
        tmp = Integer.parseInt(strrem);
        if (tmp == 0) {
            alpha[cnt] = 26;
            a = a.divide(bi26);
            a = a.subtract(bi1);
        } else {
            alpha[cnt] = tmp;
            a = a.divide(bi26);
        }
        cnt++;
    }
//for(int i=0;i<cnt;i++) {
//    System.out.println(alpha[i]);
//}

//System.out.println(cnt);
    byte[] ascii = new byte[cnt];
    for(int i=0;i<cnt;i++) {
        ascii[cnt - i -1] = (byte)(97 + alpha[i] - 1);
    }

    String outstr = new String(ascii);
    System.out.println(outstr);

}
}

