# Prime (ppc 100)
###ENG[PL](#pl-version)
In the task we get a lot of [files](encrypted.zip) with a large number as filename and a single byte as content.The goal of this task is to extract contents from all files which have a prime number as name.We do this with a simple script and gmpy2.is_prime():
```pythonimport codecsimport osfrom gmpy2 import is_prime
def main():    basedir = "/tmp/encrypted"    result = ""    for filename in os.listdir(basedir):        if is_prime(int(filename)):            with codecs.open(basedir + "/" + filename, "r") as input_file:                data = input_file.read()[:-1]                result += data    print('result', result)
main()```
Which gives the flag: `c93c0f30299130cde942fce8ec5dd0b3012dcfa478a4ab2314ee525098fb779e2812d6731d372bae6d71e220a6`
###PL version
W zadaniu dostajemy dużo [plików](encrypted.zip) z dużą liczbą jako nazwa pliku i jednym bajtem zawartości.Celem jest pobranie zawartości ze wszystkich plików, których nazwa jest liczbą pierwszą.Robimy to za pomocą skryptu i gmpy2.is_prime():
```pythonimport codecsimport osfrom gmpy2 import is_prime
def main():    basedir = "/tmp/encrypted"    result = ""    for filename in os.listdir(basedir):        if is_prime(int(filename)):            with codecs.open(basedir + "/" + filename, "r") as input_file:                data = input_file.read()[:-1]                result += data    print('result', result)
main()```
Co daje nam flage: `c93c0f30299130cde942fce8ec5dd0b3012dcfa478a4ab2314ee525098fb779e2812d6731d372bae6d71e220a6`