import re
s = """opakdpoasdkas okdaospdkpaskd okpaskdapo
akopdka huipizda
stroka
ocakpsaod"""
m = re.search(r'\b(\S+)\b(?=\s*stroka)', s)
if m:
print(m[1])
aW1wb3J0IHJlCgpzID0gIiIib3Bha2Rwb2FzZGthcyBva2Rhb3NwZGtwYXNrZCBva3Bhc2tkYXBvCmFrb3Bka2EgaHVpcGl6ZGEKc3Ryb2thCm9jYWtwc2FvZCIiIgptID0gcmUuc2VhcmNoKHInXGIoXFMrKVxiKD89XHMqc3Ryb2thKScsIHMpCmlmIG06CiAgICBwcmludChtWzFdKQ==