object test {

    @JvmStatic
    fun main(args: Array<String>) {
        println(from10to43(123))
        println(from43to10("2ъ"))
    }


    private fun from10to43(number: Int): String {

        var value = number

        val result = StringBuilder()

        while (value % 43 > 0) {
            val p = value / 43
            val q = mapping[value % 43]

            result.insert(0, q)

            if (p < 43) {
                result.insert(0, mapping[p])
                break
            } else value = p
        }
        return result.toString()
    }

    private fun from43to10(number: String): Int {
        var result = 0
        for (i in 0 until number.length) {
            val digit = mapping.entries.first { it.value == number[i].toString() }.key
            result *= 43
            result -= digit
        }
        return -result
    }

    val mapping = mapOf(0 to "0",
            1 to "1",
            2 to "2",
            3 to "3",
            4 to "4",
            5 to "5",
            6 to "6",
            7 to "7",
            8 to "8",
            9 to "9",
            10 to "а",
            11 to "б",
            12 to "в",
            13 to "г",
            14 to "д",
            15 to "е",
            16 to "ё",
            17 to "ж",
            18 to "з",
            19 to "и",
            20 to "й",
            21 to "к",
            22 to "л",
            23 to "м",
            24 to "н",
            25 to "о",
            26 to "п",
            27 to "р",
            28 to "с",
            29 to "т",
            30 to "у",
            31 to "ф",
            32 to "х",
            33 to "ц",
            34 to "ч",
            35 to "ш",
            36 to "щ",
            37 to "ъ",
            38 to "ы",
            39 to "ь",
            40 to "э",
            41 to "ю",
            42 to "я")
}