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;
using ll = long long;
using P = pair<ll, ll>;
const ll INF = 100000000;
#define rep1(i, n) for (ll i=0; i<(n); i++) 
#define rep2(i, k, n) for (ll i=k; i<(n); i++)
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<typename TypeInt>

string Itoa(const TypeInt v, int base){
	static const char table[] = "abcdefghijklmnopqrstuvwxyz";
	string ret;
	static numeric_limits<TypeInt> t;
	TypeInt n = v;
	if (t.is_signed) {
		if (v < 0) n *= -1;
	}
	while (n >= base) {
        --n;
		ret += table[n%base];
		n /= base;
	}
	ret += table[n-1];
	if (t.is_signed) {
		if (v < 0 && base == 10) ret += '-';
	}
	// 文字列の順番を逆にする
	std::reverse(ret.begin(), ret.end());

	return ret;
}



int main(void)
{
    uint64_t n;
    cin >> n;
    cout << Itoa(n, 26) << endl;
}