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.