MadelineProto/docs/docs/FLOOD_WAIT.md

Avoiding FLOOD_WAITs

If you make too many requests to telegram, you might get FLOOD_WAITed for a while.
To avoid these flood waits, you must calculate the flood wait rate.

Calculate it by making N of method calls until you get a FLOOD_WAIT_X

floodwaitrate = time it took you to make the method calls + X   

Use sleep to execute max N calls in floodwaitrate seconds, this way you won't get flood waited!