import re
p=input("Enter  a Password:")
x=True
while x:
    if(len(p)<6 or len(p)>20):
        break
    elif not re.search("[a-z]",p):
        break
    elif not re.search("[A-Z]",p):
        break
    elif not re.search("[0-9]",p):
        break
    elif not re.search("[@#$&*!]",p):
        break
    elif re.search("\s",p):
        break
    else:
        print("valid password")
        x=False

if x:
    print("invalid password")