import scala.io.StdIn._

object Main {
  def factorial(n: Int): Long = {
    def loop(i: Int, j: Long = 0): Long = i match {
      case 1 => j
      case _ => loop(i - 1, i * j)
    }
    loop(n)
  }
  
  def main(args: Array[String]): Unit = {
    println((1 to readInt()).map(_.toLong).product)
  }
}