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 C++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
 
using namespace std;
 
#define f0r(a, b) for (long long a = 0; a < (b); a++)
#define f1r(a, b, c) for (long long a = (b); a < (c); a++)
#define f0rd(a, b) for (long long a = (b); a >= 0; a--)
#define f1rd(a, b, c) for (long long a = (b); a >= (c); a--)
#define ms(arr, v) memset(arr, v, sizeof(arr))
#define pb push_back
#define mp make_pair
#define f first
#define s second
using ll = long long;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
 
void fio() {
  ios_base::sync_with_stdio(0);
  cin.tie(0); 
  cout.tie(0);
}
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
const long double pi = 3.14159265358979323846;



void solve() {
  ll n; cin >> n;

  string s;
  while (n > 0) {
    --n;
    ll v = n % 26;
    s = (char)('a' + v) + s;
    n /= 26;
  }
  cout << s << '\n';
}
 
int main() {
  fio();
  
  int T = 1;
  // cin >> T;
  while (T--) solve();
}