import java.io.PrintWriter import java.util.* import kotlin.math.* fun PrintWriter.solve() { val n = nextInt() val s = nextLine() if (s.all { it == '>' }) { println(0) return } var dp = Array(n) { Array(2) { ModInt(0) } } dp[0][0] = ModInt(1) for (i in 0 until n - 1) { val newdp = Array(n) { Array(2) { ModInt(0) } } for (j in 0..i) { if (s[i] == '>') { newdp[j][0] += dp[j][0] + dp[j][1] } newdp[j + 1][1] += dp[j][0] } dp = newdp } val c = Array(n + 1) { i -> binomSimple(2L * i, i.toLong()) / ModInt(i + 1) } var ans = ModInt(0) val p = s.count { it == '<' } % 2 for (i in 0 until n) { val num = c[n - i] * (dp[i][0] + dp[i][1]) if (i % 2 == p) { ans += num } else { ans -= num } } println(ans) } // 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 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