Flying Calculator 1.01

Flying calculator - Automatic calculation of dangerous and safe for conception days of the menstrual cycle, for several girls at once. Two figures are needed for the calculation: the duration of its cycle and any date of the beginning (first day) of the monthly.

Now you know when it's better not to bother her, and when you can not even protect yourself. Unless, of course, you are sure that you will not get infected with anything :)