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 Kotlin (1.3.71) (judge verdict: Runtime Error)

import kotlin.math.pow

fun main(args: Array<String>) {
    var n = readLong()
    println(solve(n))
}

fun solve(n: Long): String {
    var keta = 0
    var temp = 0
    for (i in 1..100) {
        if (n <= 26.0.pow(i) + temp) {
            keta = i
            break
        }
        temp = 26.0.pow(i).toInt()
    }
    var ans = ""
    var temp2 = 0L
    for (i in 1..keta) {
        var amari = (n-temp2) % 26.0.pow(i).toInt()
//        println(amari)
        ans = if (i == 1) {
            alphabet(amari.toInt()) + ans
        } else {
            alphabet2(amari.toInt()) + ans
        }
        temp2 += amari
    }
    return ans
}

fun alphabet(n: Int): String {
    val str = "abcdefghijklmnopqrstuvwxyz"
    return str[n - 1].toString()
}

fun alphabet2(n: Int): String {
    val str = "abcdefghijklmnopqrstuvwxyz"
    var amari = n % 26
    println(amari)
    var num = if (amari == 0) 25 else amari - 1
    return str[amari - 1].toString()
}

private fun read() = readLine()!!

private fun readInt() = read().toInt()

private fun readLong() = read().toLong()

private fun readDouble() = read().toDouble()

private fun readListString() = read().split(" ")

private fun readListInt() = readListString().map { it.toInt() }

private fun readListLong() = readListString().map { it.toLong() }

private fun readListDouble() = readListString().map { it.toDouble() }

private fun readMatrixString(n: Int): List<List<String>> {
    val matrix = mutableListOf<List<String>>()
    for (i in 0 until n) {
        val list = readListString()
        matrix.add(list)
    }
    return matrix
}

private fun readMatrixInt(n: Int): List<List<Int>> {
    val matrix = mutableListOf<List<Int>>()
    for (i in 0 until n) {
        val list = readListInt()
        matrix.add(list)
    }
    return matrix
}

private fun readMatrixDouble(n: Int): List<List<Double>> {
    val matrix = mutableListOf<List<Double>>()
    for (i in 0 until n) {
        val list = readListDouble()
        matrix.add(list)
    }
    return matrix
}

private fun readMatrixLong(n: Int): List<List<Long>> {
    val matrix = mutableListOf<List<Long>>()
    for (i in 0 until n) {
        val list = readListLong()
        matrix.add(list)
    }
    return matrix
}