Type the correct answer in the box. Write your answer as a whole number.
The radius of the base of a cylinder is 10 centimeters, and its height is 20 centimeters. A cone is used to fill the cylinder with water. The radius of the cone's base is 5 centimeters, and its height is 10 centimeters.
The number of times one needs to use the completely filled cone to completely fill the cylinder with water is