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 ll long long
    #define pb push_back
    #define printV(v) for(int i=0;i<v._size();i++){cout << v[i]<< " ";} cout << endl
    #define printRev(v) for(int i=v._size()-1;i >= 0;i--){cout << v[i] << " ";} cout << endl
    #define sortV(v) sort(v.begin(),v.end())
    #define revV(v) reverse(v.begin(),v.end())
    #define FOR(i,from,n) for(int i=from;i<n;i++)
    #define FOL(i,from,n) for(int i=from;i >= n;i--)

        ll a,b,c,d,e,f,g,n,m,k,t,x,h,w,p,q,y;
        string str = "";
        ll mod = 1e9 + 7;

        ll pow(ll base, ll q, ll mod){
            ll answer = 1;
            while(q > 0){
                if(q & 1LL)
                    answer = (answer * base) % mod;

                q = q >> 1LL;
                base = (base*base) % mod;
            }
            return answer % mod;
        }

        

        

        

        void solve1(){
            cin >> n;
            string s1,s2;
            cin >> s1 >> s2;
            if(s1 == s2){
                cout << "0\n";
                return;
            }
            int len1 = 0, len2 = 0;
            for(int i=0;i < n; i++){
                if(s1[i] == '1') len1++;
                if(s2[i] == '1') len2++;
            }
            if(len1 != len2) {cout << "-1\n"; return;}
        }


        void solve(){
            cin >> n;
            string answer=  "";
            while(n > 0){
                answer.pb('a' + ( (n-1)%26));
                if(n == 26) break;
                n /= 26;
            }
            revV(answer);
            cout << answer << endl;
        }

       
    


        int main(){
            ios_base::sync_with_stdio(false);

          
            

            int cases = 1;
            //cin >> cases;

            while(cases--) solve();
            return 0;

        }