Missile Defense System

You're a proud soldier in your homeland. An organized group of villains has decided to destroy your city. There are long range missiles flying on your home. Your only hope of protecting people is to shoot down missiles before they hit the ground. Most soldiers did not have the courage to go into this battle. There is just few soldiers... but not so much, you're three. Control tanks, each with 20 rockets at the beginning. When you miss the missiles,you will have one less rocket. If you hit, you will stay on the same number. So be precise and shoot down as many rockets as possible. Have fun.