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)

// Created by code_sm
//
#include<bits/stdc++.h>
using namespace std;
//#include <ext/pb_ds/assoc_container.hpp> 
//using namespace __gnu_pbds;
//typedef tree<int,null_type,less<int>,rb_tree_tag, tree_order_statistics_node_update> pseudo_set;
#define ll long long
#define vi vector<int>
#define si set<int> 
#define mii map<int,int>
#define pb push_back
#define pf push_front
#define pii pair<int,int>
#define extract_word(s)  stringstream str(s); while(str>>word)
#define fastio ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define SET(s) cout<<fixed<<setprecision(s)
#define chotu 1000000007
#define set0(a) memset(a,0,sizeof(a))
#define endl "\n"
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define lower_string(s) transform(all(s),s.begin(),::tolower())
#define upper_string(s) transform(all(s),s.begin(),::toupper())
#define size(s) s.size()
template<class T> bool umin(T &a, T b) { return a > b ? (a = b, true) : false; }
template<class T> bool umax(T &a, T b) { return a < b ? (a = b, true) : false; }
template<typename T,typename U>
bool compare(T x,U y){return(abs(x-y)<=1e-9);}
void solve()
{
fastio
	ll n;
	cin>>n;
	string res="zabcdefghijklmnopqrstuvwxy";
	string ans;
	while(n)
	{
		ans.pb(res[n%26]);
		n=ceil(n/26.0)-1;
	}
	reverse(all(ans));
cout<<ans;
}
int main()
{
//code
	#ifndef ONLINE_JUDGE
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
	#endif
fastio	
int t;
t=1;
while(t--)
{
	solve();
	cout<<endl;
}
}