import java.io.PrintWriter import java.util.* import kotlin.math.* fun PrintWriter.solve() { val n = nextInt() val s = nextLine() val p = (1..n).toMutableList() var ans = 0 loop@ do { for (i in 0 until n - 1) { if (s[i] == '<' && p[i] > p[i + 1]) { continue@loop } if (s[i] == '>' && p[i] < p[i + 1]) { continue@loop } } if (lis(p.toTypedArray()) != 2) { continue@loop } ans++ } while (nextPermutation(p)) println(ans) } fun nextPermutation(lst: MutableList): Boolean { val n = lst.size for (i in n - 2 downTo 0) { if (lst[i] < lst[i + 1]) { for (j in n - 1 downTo i + 1) { if (lst[j] > lst[i]) { lst[i] = lst[j].also { lst[j] = lst[i] } val tmpArray = lst.takeLast(n - (i + 1)).sorted() tmpArray.forEachIndexed { index, e -> lst[i + 1 + index] = e } return true } } } } return false } // region ModInt class ModInt(x: Long) { companion object { //const val MOD = 1000000007L const val MOD = 998244353L } 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 //広義のLIS fun lis(a: Array): Int { val lst = mutableListOf() for (v in a) { if ((lst.lastOrNull() ?: -1) <= v) { lst.add(v) } else { if (lst[0] > v) { lst[0] = v } else { var left = 0 var right = lst.size - 1 while (right - left > 1) { val mid = (left + right) / 2 if (lst[mid] < v) { left = mid } else { right = mid } } lst[right] = v } } } return lst.size } 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