object Main { def main(args: Array[String]): Unit = { val s = new Main() s.solve() s.out.flush() } } class Main { import java.io._ import java.util.StringTokenizer import scala.collection.mutable import scala.util.Sorting import math.{abs, max, min} import mutable.{ArrayBuffer, ListBuffer} import scala.reflect.ClassTag val MOD = 1000000007 val out = new PrintWriter(System.out) def solve(): Unit = { val N = nl() // val MAX = 3 val MAX = 32 implicit def toInt(b: Boolean): Int = if (b) 1 else 0 val memo = Array.fill[Long](MAX, MAX, 2, 2)(-1) def calc(k: Int, i: Int, less: Boolean, found: Boolean): Long = { if (i == MAX) toInt(found) else { if (memo(k)(i)(less)(found) == -1) { var res = 0L val b = ((N >> (MAX - 1 - i)) & 1).toInt val limit = if (less) 1 else b.toInt REP(limit + 1) { d => res += calc(k, i + 1, less || (d < b), found || (i == k && d == 1)) } memo(k)(i)(less)(found) = res } memo(k)(i)(less)(found) } } val ok = map(MAX) { k => calc(k, 0, false, false) }.exists(_ % 2 != 0) // REP(MAX) { k => // System.err.println(s"$k ${calc(k, 0, false, false)}") // } if (ok) out.println("O") else out.println("X") } class InputReader(val stream: InputStream) { private val reader = new BufferedReader(new InputStreamReader(stream), 32768) private var tokenizer: StringTokenizer = _ def next(): String = { while (tokenizer == null || !tokenizer.hasMoreTokens) tokenizer = new StringTokenizer(reader.readLine) tokenizer.nextToken } def nextInt(): Int = next().toInt def nextLong(): Long = next().toLong def nextChar(): Char = next().charAt(0) } val sc = new InputReader(System.in) def ni(): Int = sc.nextInt() def nl(): Long = sc.nextLong() def nc(): Char = sc.nextChar() def ns(): String = sc.next() def ns(n: Int): Array[Char] = ns().toCharArray def na(n: Int, offset: Int = 0): Array[Int] = map(n)(_ => ni() + offset) def na2(n: Int, offset: Int = 0): (Array[Int], Array[Int]) = { val A1, A2 = Array.ofDim[Int](n) REP(n) { i => A1(i) = ni() + offset A2(i) = ni() + offset } (A1, A2) } def nm(n: Int, m: Int): Array[Array[Int]] = { val A = Array.ofDim[Int](n, m) REP(n) { i => REP(m) { j => A(i)(j) = ni() } } A } def nal(n: Int): Array[Long] = map(n)(_ => nl()) def nm_c(n: Int, m: Int): Array[Array[Char]] = map(n) (_ => ns(m)) def REP(n: Int, offset: Int = 0)(f: Int => Unit): Unit = { var i = offset val N = n + offset while(i < N) { f(i); i += 1 } } def REP_r(n: Int, offset: Int = 0)(f: Int => Unit): Unit = { var i = n - 1 + offset while(i >= offset) { f(i); i -= 1 } } def map[@specialized A: ClassTag](n: Int, offset: Int = 0)(f: Int => A): Array[A] = { val res = Array.ofDim[A](n) REP(n)(i => res(i) = f(i + offset)) res } def sumL(as: Array[Int]): Long = { var s = 0L REP(as.length)(i => s += as(i)) s } def cumSum(as: Array[Int]) = { val cum = Array.ofDim[Long](as.length + 1) REP(as.length) { i => cum(i + 1) = cum(i) + as(i) } cum } }