import sys, math
sys.setrecursionlimit(1000000)
INF = 1 << 100
mod = 1000000007
#mod = 998244353
input = lambda: sys.stdin.readline().rstrip()
li = lambda: list(map(int, input().split()))

N = int(input())
if N & 1:
    print(1)
else:
    print(N//2)