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)

//I am so vegetable
//#define err
#pragma GCC optimize(2)
#include <bits/stdc++.h>
#define FIO ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define PB push_back
#define IN insert
#define ER erase
#define CT count
#define EP empty
#define _for(i,a,b) for(int i = (a);i<(b);++i)
#define _rfor(i,a,b) for(int i = (a);i>(b);--i)
#define _sfor(p,st) for(auto &p:st)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9+7;
const double eps = 1e-6;
const double pi = acos(-1.0);
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
ll qpow(ll x, ll y) { ll ans = 1; for (; y > 0; y >>= 1) { if (y & 1)ans *= x; x *= x; }return ans; }
ll qpow(ll x, ll y, int MOD) { ll ans = 1; for (; y > 0; y >>= 1) { if (y & 1)ans = ans*x%MOD; x = x*x%MOD; }return ans; }
void exgcd(ll a,ll b,ll &x,ll &y){
    if(!b){x=1;y=0;return;}
    exgcd(b,a%b,x,y);
    ll X=x;
    x=y; y=X-a/b*y;
}
ll inv(ll x, int mod = MOD) { return qpow(x, mod - 2) % mod; }
ll m_m(ll a){ return (a%MOD+MOD)%MOD; }

int a[20];
int main() {
	//ofstream cout("E:\\acm dream\\out.txt",ios::out);
	FIO;
    #ifdef err
	double be = clock();
    #endif
    ll n;cin>>n;
    int cnt = 0;
    while(n){
        a[cnt++]=n%26;
        n/=26;
    }
    _rfor(i,cnt-1,-1){
        cout<<(char)(a[i]-1+'a');
    }
    #ifdef err
	double en = clock();
    cout<<"time: "<<fixed<<setprecision(8)<<en-be;
    #endif
	return 0;
}