import java.io.PrintWriter import java.util.* import kotlin.math.* // 置換の積を計算 fun prod(p: Array, q: Array): Array { val n = p.size val r = Array(n) { 0 } for (i in 0 until n) { r[i] = q[p[i] - 1] } return r } // 置換aに置換cを共役として作用させる fun conjugate(a: Array, c: Array): Array { val b = Array(6) { 0 } for (i in 0 until 6) { b[c[i] - 1] = c[a[i] - 1] } return b } // ある外部自己同型による像を計算 fun image(a: Array): Array { val n = 6 var p = Array(n) { it + 1 } val base = arrayOf( arrayOf(2, 1, 4, 3, 6, 5), // (1,2)の像 arrayOf(4, 5, 6, 1, 2, 3), // (2,3)の像 arrayOf(3, 4, 1, 2, 6, 5), // (3,4)の像 arrayOf(2, 1, 6, 5, 4, 3), // (4,5)の像 arrayOf(4, 3, 2, 1, 6, 5) // (5,6)の像 ) for (i in 0 until n) { for (j in 1 until n) { if (a[j] < a[j - 1]) { a[j] = a[j - 1].also { a[j - 1] = a[j] } p = prod(p, base[j - 1]) } } } return p } fun PrintWriter.solve() { val n = nextInt() val k = nextInt() var ans = ModInt(k) * (1..n - k).map { ModInt(it) }.fold(ModInt(1), ModInt::times) if (n == 6) { val c = (1..n).toMutableList() var count = 0 do { var ok = true val f = Array(n) { it + 1 } for (i in 0 until k - 1) { f[i] = i + 2 } f[k - 1] = 1 val g = image(conjugate(f, c.toTypedArray())) for (i in 0 until k - 1) { if (g[i] != i + 2) { ok = false break } } if (g[k - 1] != 1) ok = false if (ok) count++ } while (nextPermutation(c)) ans += ModInt(count) } else if (n == 2) { ans = ModInt(1) } println(ans) } fun nextPermutation(array: MutableList): Boolean { for (i in array.size - 2 downTo 0) { if (array[i] < array[i + 1]) { for (j in array.size - 1 downTo i + 1) { if (array[j] > array[i]) { val tmp = array[i] array[i] = array[j] array[j] = tmp val tmpArray = array.takeLast(array.size - (i + 1)).sorted() tmpArray.forEachIndexed { index, e -> array[i + 1 + index] = e } return true } } } } return false } // region ModInt class ModInt(x: Long) { companion object { const val MOD = 998244353L //const val MOD = 1000000007L } constructor(y: Int) : this(y.toLong()) val x = (x % MOD + MOD) % MOD operator fun plus(other: ModInt): ModInt { return ModInt(x + other.x) } operator fun minus(other: ModInt): ModInt { return ModInt(x - other.x) } operator fun times(other: ModInt): ModInt { return ModInt(x * other.x) } operator fun div(other: ModInt): ModInt { return this * other.inv() } fun pow(exp: Long): ModInt { if (exp == 0L) return ModInt(1L) var a = pow(exp shr 1) a *= a if (exp and 1L == 0L) return a return this * a } fun inv(): ModInt { return this.pow(MOD - 2) } override fun equals(other: Any?): Boolean { if (this === other) return true if (javaClass != other?.javaClass) return false other as ModInt if (x != other.x) return false return true } override fun hashCode(): Int { return x.hashCode() } override fun toString(): String { return "$x" } } fun Long.toModInt(): ModInt { return ModInt(this) } fun Int.toModInt(): ModInt { return ModInt(this) } fun binomSimple(n: Long, k: Long): ModInt { var numer = ModInt(1) var denom = ModInt(1) for (i in 0 until k) { numer *= ModInt(n - i) denom *= ModInt(k - i) } return numer / denom } // endregion fun main() { Thread(null, { val writer = PrintWriter(System.out, false) writer.solve() writer.flush() }, "solve", abs(1L.shl(26))) .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } } .apply { start() }.join() } // region Scanner private var st = StringTokenizer("") private val br = System.`in`.bufferedReader() fun next(): String { while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine()) return st.nextToken() } fun nextInt() = next().toInt() fun nextLong() = next().toLong() fun nextLine() = br.readLine() fun nextDouble() = next().toDouble() // endregion