1000000000000001 dogs suddenly appeared under the roof of Roger's house, all of which he decided to keep. The dogs had been numbered 1 through 1000000000000001, but he gave them new names, as follows:

* the dogs numbered 1,2,\cdots,26 were respectively given the names `a`, `b`, ..., `z`;
* the dogs numbered 27,28,29,\cdots,701,702  were respectively given the names `aa`, `ab`, `ac`, ..., `zy`, `zz`;
* the dogs numbered 703,704,705,\cdots,18277,18278  were respectively given the names `aaa`, `aab`, `aac`, ..., `zzy`, `zzz`;
* the dogs numbered 18279,18280,18281,\cdots,475253,475254  were respectively given the names `aaaa`, `aaab`, `aaac`, ..., `zzzy`, `zzzz`;
* the dogs numbered 475255,475256,\cdots  were respectively given the names `aaaaa`, `aaaab`, ...;
* and so on.



To sum it up, the dogs numbered 1, 2, \cdots were respectively given the following names:

`a`, `b`, ..., `z`, `aa`, `ab`, ..., `az`, `ba`, `bb`, ..., `bz`, ..., `za`, `zb`, ..., `zz`, `aaa`, `aab`, ..., `aaz`, `aba`, `abb`, ..., `abz`, ..., `zzz`, `aaaa`, ...

Now, Roger asks you:

"What is the name for the dog numbered N?"

Constraints

* N is an integer.
* 1 \leq N \leq 1000000000000001

Input

Input is given from Standard Input in the following format:


N


Output

Print the answer to Roger's question as a string consisting of lowercase English letters.

Examples

Input

2


Output

b


Input

27


Output

aa


Input

123456789


Output

jjddja
#!/usr/bin/env python
from __future__ import division, print_function

import os
import sys
import string
from io import BytesIO, IOBase

if sys.version_info[0] < 3:
    from __builtin__ import xrange as range
    from future_builtins import ascii, filter, hex, map, oct, zip


def main():
    n = int(input())
    n -= 1

    sol = []

    while n != -1:
        sol.append(string.ascii_lowercase[n % 26])
        n //= 26
        n -= 1

    print(*sol[::-1], sep='')


# region fastio

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", "\n"))
    if kwargs.pop("flush", False):
        file.flush()


if sys.version_info[0] < 3:
    sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
else:
    sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)

input = lambda: sys.stdin.readline().rstrip("\r\n")

# endregion

if __name__ == "__main__":
    main()
