#Write a generator, genPrimes, that returns the sequence of prime numbers
#on successive calls to its next() method: 2, 3, 5, 7, 11, ...

def genPrimes():
    primes = []   # primes generated so far
    last = 1      # last number tried
    while True:
        last += 1
        for p in primes:
            if last % p == 0:
                break
        else:
            primes.append(last)
            yield last

p = genPrimes()