Write a function to compute the multinomial coefficient for an arbitrary number of piles with ki in the first, k2 in the second, etc. Demonstrate your program works by showingit gets the correct answer on several interesting examples. 3.9 If Alice can generate a billion contracts per second, how long will it take her to mount a birthday attack for b = 32, 64, 128, and 256? Express your answer in human units (eg years, days, hours, or seconds) as appropriate. 3.10 Write a function to compute the multinomial coefficient for an arbitrary number of piles with ki in the first, k2 in the second, etc. Demonstrate your program works by showingit gets the correct answer on several interesting examples. 3.9 If Alice can generate a billion contracts per second, how long will it take her to mount a birthday attack for b = 32, 64, 128, and 256? Express your answer in human units (eg years, days, hours, or seconds) as appropriate. 3.10