object Pi {
  class PiIterator extends Iterable[BigInt]{
    var r:BigInt=0
    var q, t, k:BigInt=1
    var n, l:BigInt=3
    var nr, nn:BigInt=0
		
    def iterator: Iterator[BigInt]=new Iterator[BigInt]{
      def hasNext=true
      def next():BigInt={
        while((4*q+r-t) >= (n*t)) {
          nr = (2*q+r)*l
          nn = (q*(7*k)+2+(r*l))/(t*l)
          q = q * k
          t = t * l
          l = l + 2
          k = k + 1
          n  = nn
          r  = nr			
        }
        val ret=n
        nr = 10*(r-n*t)
        n  = ((10*(3*q+r))/t)-(10*n)
        q  = q * 10
        r  = nr
        ret
      }
    }
  }

  def main(args: Array[String]): Unit = {
    val it=new PiIterator
    println((it head) + "." + (it take 300 mkString))
  }
}