import math
n = str(math.factorial(int(input())))
count = 0
for ch in reversed(list(n)):
    if ch == '0':
        count += 1
    else:
        break
print(count)

33c828263f87af6b4ef91ee3c705b2d53b2a37f5
<mask token>

<mask token>
for ch in reversed(list(n)):
    if ch == '0':
        count += 1
    else:
        break
print(count)

<mask token>
n = str(math.factorial(int(input())))
count = 0
for ch in reversed(list(n)):
    if ch == '0':
        count += 1
    else:
        break
print(count)

import math
n = str(math.factorial(int(input())))
count = 0
for ch in reversed(list(n)):
    if ch == '0':
        count += 1
    else:
        break
print(count)
