There is a blonde, a redhead and a brunette on the stairway to heaven.
God says, "There are 3,000 steps and I'll tell you a joke on each 1,000th step you reach. If you laugh you go to hell."
So they start walking and reach to the first 1,000th step. God tells a joke, the brunette laughs and goes to hell.
Then on the 2,000th step God tells a joke, the redhead laughs and goes to hell.
On the 3,000th step God tells a joke, the blonde doesn't laugh and proceeds to the gate.
Suddenly, she bursts out laughing. God asks, "what are you laughing about?", so she replies, "I just got the first joke!".