Tennis Balls

Officially now ,i have lost 12/15 tennis balls..the first one was when i start playing tennis a month ago.. i try to serve from my house yard and accidently it went straight into the drain..the second was the cheap ball i bought RM 20 for 9 balls....normally 3 balls RM 20(cause it's high standard) ....yesterday was the day all the 9 balls fly to my house roof..and yesterday morning while waiting for mom to reverse the car i practice my serve at the field infront of my house ..again the high standard balls fly into a bigger drain..and today i practice in my room and lost another high standard balls...now i only had 3 balls left with me