on mouseUp
  ask "Number:"
  put it into number
  put number & " has factor " & factorPR(number)
end mouseUp

function factorPR number
  put random(number-4)+2 into rabbit1
  put (rabbit1*rabbit1 + 1) mod number into rabbit2
  repeat while (gcd(rabbit1 - rabbit2 + number & "," & number) is 1)
    put (rabbit1*rabbit1 + 1) mod number into rabbit1
    put (rabbit2*rabbit2 + 1) mod number into rabbit2
    put (rabbit2*rabbit2 + 1) mod number into rabbit2
  end repeat
  return gcd(rabbit1 - rabbit2 + number & "," & number)
end factorPR

function gcd params
  put item 1 of params into num1
  put item 2 of params into num2
  if (num1 > num2) then
    put num1 into temp
    put num2 into num1
    put temp into num1
  end if
  repeat forever
    put num2 - num1 * trunc(num2/num1) into num2
    if (num2 is 0) then return num1
    put num1 - num2 * trunc(num1/num2) into num1
    if (num1 is 0) then return num2
  end repeat
end gcd