if name == 'main': inp = open("input.txt", "r") out = open("output.txt", "w") prev = 1.0 primeCount = 0 while True: line = inp.readline() if prev == 0.0: break prev = float(line.strip()) if prev == 2.0 or prev == 3.0: primeCount += 1 elif prev > 3.0: isPrime = False i = 2.0 while i * i <= prev: if prev % i == 0.0: isPrime = False break isPrime = True i += 1.0 if isPrime: primeCount += 1 out.write(str(primeCount))