import sys
input = sys.stdin.readline
def iinput(): return int(input())
def sinput(): return input().rstrip()
def i0input(): return int(input()) - 1
def linput(): return list(input().split())
def liinput(): return list(map(int, input().split()))
def miinput(): return map(int, input().split())
def li0input(): return list(map(lambda x: int(x) - 1, input().split()))
def mi0input(): return map(lambda x: int(x) - 1, input().split())
INF = 10**20
MOD = 1000000007

N = iinput()
ctr = 0

while N > 0:
    ctr += 1
    N -= 1
    if ctr % 7 == 0:
        N += 6
    if N == 0:
        print(ctr)
        exit()