Competitive doubling of a number using only channels

There is a global variable (integer) and ten goroutines, each of which:

• Multiplies this variable by 2.
• Stops when the value reaches or exceeds 1000. The main goroutine must terminate all other goroutines and output the final result.

Requirements:

• It is forbidden to use sync packages (mutexes, WaitGroup) and sync/atomic.
• The entire synchronization and data transfer mechanism must be built solely on channels.