题解 | #字符串排序#
汽水瓶
http://www.nowcoder.com/practice/fe298c55694f4ed39e256170ff2c205f
while True:
try:
n = int(input())
if n != 0:
if n < 3:
print(0)
elif n == 3:
print(1)
else:
print(n//2)
except:
break
