#!/usr/bin/env gbs3

Sub GetPrimes(N As Integer) As Integer[]

  Dim aRes As New Integer[]
  Dim S As Integer[]
  Dim I, J, M As Integer
  Dim iMRoot, iHalf As Integer
 
  If N < 2 Then Return aRes

  If N = 2 Then Return [ 2 ]

  S = New Integer[(N - 3 + 1) \ 2]
  For J = 3 To N Step 2
    S[I] = J
    Inc I
  Next

  iMRoot = Sqr(N)
  iHalf = S.Count
  I = 0
  M = 3
  
  While M <= iMRoot
  
    If S[I] Then
      J = (M * M - 3) \ 2
      S[J] = 0
      While J < iHalf
	S[J] = 0
	J += M
      Wend
    Endif

    Inc I
    M = 2 * I + 3

  Wend

  aRes.Add(2)
  For Each I In S
    If I Then aRes.Add(I)
  Next

  Return aRes

End

Dim aRes As Integer[]
Dim I As Integer

For I = 1 To 10
  aRes = GetPrimes(10000000)
  Print aRes.Count
Next