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 int long long
#define dll double long long
#define forei(i,n,x) for(int i=n;i<=x;i++)
#define fored(i,n,x) for(int i=n;i>=x;i--)
#define forni(i,n,x) for(int i=n;i<x;i++)
#define fornd(i,n,x) for(int i=n;i>x;i--)
#define SQ(a) (a)*(a)
#define MOD 1000000007
#define sortvi(v) sort(v.begin(),v.end())
#define sortvd(v) sort(v.rbegin(),v.rend())
#define pb push_back
#define pob pop_back
#define mp make_pair
#define pv(v) for(auto it: v) cout<<it
#define endl '\n'   //Take care in case of interactive problems
#define  MAX2 200005
#define  MAX1 100005
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
#define INPA(arr,n) forni(i,1,n)cin>>arr[i]


typedef pair<ll,ll> pl;
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;


int main()
{
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL); 
    /* write your code here */
    
    ll n;cin>>n;
    ll temp;
    string s={};
    char c;
    while(n>26)
    {
        temp = n%26;
        if(temp==0)
        {
            s.append("z");
            n--;
        }
        else
        {
         c = 'a' + temp-1;
            s.append(1,c);
        }
        
        n = n/26;
    }
    
        temp = n%26;
  //      cout<<temp<<endl;
        if(temp==0)
        {
            s.append("z");
        }
        else
        {
            c = 'a' + temp-1;
            s.append(1,c);
        }
        
    
     reverse(s.begin(),s.end());
    cout<<s<<endl;
    
    return 0;
}