How did "we" get enlisted for this project? It's five lines of Python.

Code:

Primes = [101, 103, etc.] # You fill in the primes you care about.
product = 1
for prime in Primes :
product *= ((prime - 1)/prime)
print(str(product))

You initialize a list called Primes with the list of primes, which you can look up or calculate.

ps -- This is Python3, which defines '/' as real number division.