def na10(dana):
pom = 0
for i in range(len(dana)):
x = int(dana[- i -1])
pom = pom + x * 2 ** 1
return pom
print(na10("10100101"))
ZGVmIG5hMTAoZGFuYSk6Cglwb20gPSAwCglmb3IgaSBpbiByYW5nZShsZW4oZGFuYSkpOgoJCXggPSBpbnQoZGFuYVstIGkgLTFdKQoJCXBvbSA9IHBvbSArIHggKiAyICoqIDEKCXJldHVybiBwb20KCXByaW50KG5hMTAoIjEwMTAwMTAxIikpIA==