def safe_base64_decode(s):

    if len(s)%4==0:

      return base64.b64decode(s)

    else:

      a=len(s)%4

      s=s+a*b'='

      return base64.b64decode(s)

def safe_base64_decode(s):

    while len(s)%4!=0:

      s=s+b'='

    return base64.b64decode(s)