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: Wrong Answer)

#include <bits/stdc++.h>

using namespace std;
#define DBG(x)                         \
    (void)(cout << "L" << __LINE__     \
                << ": " << #x << " = " \
                << (x) << '\n')
#define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x))
#define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x))
typedef long long ll;
using pii = pair<int, int>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const long double PI = (acos(-1));
const long double EPS = 0.0000000001;
const int INF = 0x3f3f3f3f;
const int maxn = 1100000;

void run_case()
{
    ll x;
    cin >> x;
    vector<int> p;
    while (x)
    {
        int cur = x % 26;
        p.push_back(cur);
        x /= 26;
    }
    for (int i = p.size() - 1; i >= 0; i--)
    {
        cout << char(p[i] + 'a' - 1);
    }
    cout << "\n"; 
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setiosflags(ios::fixed) << setprecision(12);
    run_case();
    cout.flush();
    return 0;
}