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 MOD 1000000007
#define ll long long
#define pb push_back
#define mp make_pair
bool isPrime(ll n) 
{ 
    
    if (n <= 1)  return false; 
    if (n <= 3)  return true; 
   
    if (n%2 == 0 || n%3 == 0) return false; 
  
    for (ll i=5; i*i<=n; i=i+6) 
        if (n%i == 0 || n%(i+2) == 0) 
           return false; 
  
    return true; 
} 
int minthis(int a, int b){
if(a < b){
return a;
}
return b;
}
int maxthis(int a, int b){
if(a > b){
return a;
}
return b;
}
int gcd(int a, int b){
    if( a<0 ) a = -a;
    if( b<0 ) b = -b;
    while( b!=0 ){
        a %= b;
        if( a==0 ) return b;
        b %= a;
    }
    return a;
}
 
int findLargestDivisor(int n) 
{ 
	int max = 1;
    for (int i = 2; i < n; i++) {        
        if(n %(i) == 0) { 
            max = i;
        } 
    }
    return max;     
} 
 
 
ll power(ll x, ll y)  
{  
    ll temp;  
    if(y == 0)  
        return 1;  
    temp = power(x, y / 2);  
    if (y % 2 == 0)  
        return temp * temp;  
    else
    {  
        if(y > 0)  
            return x * temp * temp;  
        else
            return (temp * temp) / x;  
    }  
}  
 /*
const int mxN = 200005;
int father[mxN] = {}, level[mxN] = {}, subtree[mxN] = {}, count_sons[mxN] = {};vector<int> e[mxN];priority_queue<pair<int,int>> pq; 
 
 
void dfs(int node, int fr){
	father[node] = fr;
	for(auto x : e[node]){
		if(x != fr){
			count_sons[node]++;
			level[x] = level[node]+1;
			dfs(x,node);
		}
	}
	if(count_sons[node] == 0){
		
		pq.push({node, level[node]});
		cout << node << endl;
	}
} 
	
 */

void solve(){	
	ll n;
	cin >>n;
	char arr[27];
	int k = 1;
	for(int i = 97 ; i<= 122 ; i++){
		arr[k] = (char)i;
		k++;
	}	
	ll no = n;
	ll count = 0;
	while(n/26 > 0){
		count++;n/=26;
	}
	for(ll i = count; i >=0 ; i--){ 
	cout << arr[(no / power(26,i))%26] ;
	}	
}
  
int main(){ 
	ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int t = 1;    
    //cin >> t;
    while(t--){
		solve();
	}
    return 0; 
}