Counting On The Tracks

There's a brunette walking down a set of railroad tracks saying, "21, 21, 21..." Then a blonde pulls up, gets out of her car, and says, "What are you doing?"

The brunette replies, "Just counting."

The blonde says, "May I join you?"

"Yes," replies the brunette.

So the blonde and the brunette are now both walking down the railroad tracks saying, "21, 21, 21..." A train comes and the brunette jumps off the tracks as the blonde gets hit. After the train passes, the brunette gets back on the tracks and says, "22, 22, 22..."