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 FastIO ios_base :: sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define read(in) freopen("Input.txt","r",stdin)
#define write(out) freopen("Ouput.txt","w",stdout)
#define pf printf
#define sf scanf
#define fr(i,n) for(i=1 ; i<=n ; i++)
#define fr1(i,x,n) for(i=x ; i<=n ; i++)
#define sf1(val) scanf("%lld",&val)
#define sf2(val1,val2) scanf("%lld %lld",&val1,&val2)
#define INF 999999999999999999
#define Pi 2*acos(0.0)
#define len 200000

typedef long long int lli;

lli a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,sum=0,total=0,res=0,ans=0;

int main()
{
    //FastIO;

    //read(in);

    sf1(t);

    vector<char>ar;
    char ch;

    sum=t;

    while(1)
    {
        res=sum%26;

        if(res==0)  ch='z';

        else ch='a'+res-1;

        ar.push_back(ch);

        sum=sum/26;

        if(sum==0)     break;
    }

    fr(i,ar.size()) pf("%c",ar[ar.size()-i]);

    pf("\n");
}