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)


fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let mut input = s
        .split_whitespace()
        .nth(0)
        .unwrap()
        .parse::<i128>()
        .unwrap()
        - 1;
    let mut result = String::new();
    loop {
        let v = input % 26;
        match v {
            0 => result.push('a'),
            1 => result.push('b'),
            2 => result.push('c'),
            3 => result.push('d'),
            4 => result.push('e'),
            5 => result.push('f'),
            6 => result.push('g'),
            7 => result.push('h'),
            8 => result.push('i'),
            9 => result.push('j'),
            10 => result.push('k'),
            11 => result.push('l'),
            12 => result.push('m'),
            13 => result.push('n'),
            14 => result.push('o'),
            15 => result.push('p'),
            16 => result.push('q'),
            17 => result.push('r'),
            18 => result.push('s'),
            19 => result.push('t'),
            20 => result.push('u'),
            21 => result.push('v'),
            22 => result.push('w'),
            23 => result.push('x'),
            24 => result.push('y'),
            25 => result.push('z'),
            _ => {}
        }
        //result = ('a' + v) as char +s result;

        input = input / 26 - 1;
        if input < 0 {
            break;
        }
    }
    println!("{}", result.chars().rev().collect::<String>());
}