import sys
from functools import partial
print(sum(chunk.count('\n') for chunk in iter(partial(sys.stdin.read, 1 << 15), '')))
aW1wb3J0IHN5cwpmcm9tIGZ1bmN0b29scyBpbXBvcnQgcGFydGlhbAoKcHJpbnQoc3VtKGNodW5rLmNvdW50KCdcbicpIGZvciBjaHVuayBpbiBpdGVyKHBhcnRpYWwoc3lzLnN0ZGluLnJlYWQsIDEgPDwgMTUpLCAnJykpKQo=
JCBwdiBvdXQudHh0IHwgd2MgLWwKICA5OU1CIDA6MDA6MDAgWyA4NDBNQi9zXSBbPT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0mZ3Q7XSAxMDAlICAgICAgICAgICAgCjIwNTUzMTIKCiQgcHYgb3V0LnR4dCB8IHB5dGhvbiBjb3VudC1saW5lcy5weQogIDk5TUIgMDowMDowMCBbIDY2ME1CL3NdIFs9PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PSZndDtdIDEwMCUgICAgICAgICAgICAKMjA1NTMxMgo=
$ pv out.txt | wc -l
99MB 0:00:00 [ 840MB/s] [=========================================>] 100%
2055312
$ pv out.txt | python count-lines.py
99MB 0:00:00 [ 660MB/s] [=========================================>] 100%
2055312