Problem:
Score : 300 points

Problem Statement

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.

Sample Input 1

2

Sample Output 1

b

Sample Input 2

27

Sample Output 2

aa

Sample Input 3

123456789

Sample Output 3

jjddja

Solution in Lua (Lua 5.3.5) (judge verdict: Wrong Answer)

local t = {"a", "b", "c", "d", "e","f", "g", "h", "i","j", "k", "l", "m", "n","o", "p", "q", "r","s", "t ", "u", "v", "w","x", "y", "z"}
local N = io.read()
-- local N = 26
local x = string.byte("a") - 1
local aa = ""
local function a(N)
    local n = math.floor(N / 26)
    local m = N % 26
    if n > 26 then
       a(n)
    else
        if m ~= 0 and n ~= 0 then
            aa = aa..t[n]
        end
    end
    if m == 0 then
        aa = aa..t[26]
    else
        aa = aa..t[m]
    end
end
a(N)
print(aa)