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)

#include <bits/stdc++.h>
using namespace std;
#define ll long long int 
#define IOS ios_base::sync_with_stdio(false);cin.tie(NULL);
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define mx *max_element
#define mn *min_element
#define fo(i,n) for(ll i=0;i<n;i++)
#define loop(i,a,b) for(ll i=a;i<=b;i++)
#define rfo(i,n) for(ll i=n-1;i>=0;i--)
#define rloop(i,a,b) for(ll i=a;i>=b;i--)
#define all(x) x.begin(),x.end()
#define sortall(x) sort(all(x))
#define precision cout<<fixed<<setprecision(10)
#define mem(x,p) memset(x,p,sizeof(x))
#define w(t) ll t;cin>>t;while(t--)
#define kk "\n"
#define setbits(x) __builtin_popcountll(x)
const double pi=3.1415926535897932384626;
//const ll mod = 998244353;
const ll mod=1e9+7;
int main()
{
  IOS
  ll n;
  cin>>n;
  string s="";
  while(n>0)
  {
    ll p=n%26;
    n=n/26;
    if(p==0)
      n--;
    p=(p+25)%26;
    s=s+(char)(p+'a');
  }
  reverse(s.begin(),s.end());
  cout<<s;
  return 0;
}