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: Runtime Error)

use proconio::input;

fn main() {
    input! {
        mut n: i32,
    }
    let alph = vec!["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l",
                    "m", "n", "p", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"];

    let mut acc = n;

    if n < 27 {
        let n = n as usize;
    }

    let mut nums:Vec<i32> = vec![];

    let one = n % 26;


    let mut cnt = 0; // cnt of num div by 26
    while acc > 26 {
        cnt +=1;
        acc /= 26;
    }

    for i in (1..cnt+1).rev() {
        nums.push(n/(26i32.pow(i)));
        n %= 26i32.pow(i);
    }
    nums.push(one);
    for i in nums.iter() {

        print!("{}", alph[*i as usize-1]);

    }
    println!("");

}