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 Rust (1.42.0) (judge verdict: Accepted)

use std::io;

fn procon_read<T: std::str::FromStr>() ->  Vec<T> {
    let mut buf = String::new();
    io::stdin().read_line(&mut buf).expect("");
    let iter = buf.split_whitespace();
    let mut v: Vec<T> = Vec::new();
    for i in iter {
        v.push(i.parse().ok().unwrap());
    }
    v
}

fn main() {
    let v:Vec<u128> = procon_read();
    let mut n = v[0];
    let mut v:Vec<char> = Vec::new();
    while n != 0 {
        if n%26 == 0 {
            // print!("z");
            v.push('z');
            n = n/26 - 1;
        }else{
            // print!("{}", (('a' as u8) - 1_u8 + (n%26) as u8) as char);
            v.push((('a' as u8) - 1_u8 + (n%26) as u8) as char);
            n = n /26;
        }
    }
    
    for i in (0..v.len()).rev() {
        print!("{}", v[i]);
    }
    println!("");
}