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)

/*;

THE BEST IS YET TO COME

*/
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define r(i, s, l) for (int i = s; i < l; i++)
#define rr(i,s,l) for(int i=s;i>=l;i--)
#define mod 1000000007
#define INT_BITS 32
#define ld long double
#define pp pair<int,int>
#define ss second
#define ff first
#define INF 1e18
#define N 2000005
#define all(a) a.begin(), a.end()
#define pb push_back
#define vi vector<int>
#define vip vector<pair<int,int> >
#define endl "\n"
#define ln length()
#define sz size()
using namespace std;
void fast()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}
signed main()
{

    int n;
    cin>>n;
    vector<int> arr(N);
	int i = 0;
	while (n) {
		arr[i] = n % 26;
		n = n / 26;
		i++;
	}


	for (int j = 0; j < i - 1; j++) {
		if (arr[j] <= 0) {
			arr[j] += 26;
			arr[j + 1] = arr[j + 1] - 1;
		}
	}

	for (int j = i; j >= 0; j--) {
		if (arr[j] > 0)
			cout << char('a' + arr[j] - 1);
	}


	return 0;
}