FZU 2167 大王叫我来巡山呐

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<iostream>
#include<algorithm>
#include<queue>
#include<stack>
#define mem(a,b) memset(a,b,sizeof(a))
#define ll __int64
#define MAXN 1000
#define INF 0x7ffffff
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
using namespace std;
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        int coun,ans;
        coun=n/7;
        ans=2*coun;
        if((n+1)/7!=coun)//加一天 多一周 则必然为周六
        ans++;
        cout<<ans<<endl;
    }
    return 0;
}