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;
int s, t, n, m;
void chkmax(int &a, int b) {a = a > b ? a : b;}
void chkmin(int &a, int b) {a = a < b ? a : b;}
int read() {
	int x = 0, f = 1; char c = getchar();
	while(!isdigit(c)) {
		if(c == '-') f = -f;
		c = getchar();
	}
	while(isdigit(c)) {
		x = (x << 1) + (x << 3) + c - '0';
		c = getchar();
	}
	return x * f;
}
void write(int x) {
	char c[33] = {0}, tot = 0;
	if(x == 0) {puts("0"); return;}
	while(x) {c[++ tot] = x % 10 + '0'; x /= 10;}
	while(tot) {putchar(c[tot --]);}
	return ;
}
long long tmp;
string str;
void calc() {
	while(tmp) {
		str = (char)('a' + (tmp - 1) % 26) + str;
		tmp /= 26;
	} 
	cout << str;
}
int main() {
	cin >> tmp;
	calc();
	return 0;
}