#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    ll now = 0;
    ll cnt = 0;
    srep(i,2015,2415){
        if(i % 400 == 0){
            now += 366;
        }else if(i % 100 == 0){
            now += 365;
        }else if(i % 4 == 0){
            now += 366;
        }else{
            now += 365;
        }
        if(now % 7 == 0) cnt++;
    }
    cnt *= 10;

    ll n;
    cin >> n;
    ll ans = 0;

    while(n - 4000 >= 2015){
        n -= 4000;
        ans += cnt;
    }

    now = 0;
    srep(i,2015,n+1){
        if(i % 400 == 0){
            now += 366;
        }else if(i % 100 == 0){
            now += 365;
        }else if(i % 4 == 0){
            now += 366;
        }else{
            now += 365;
        }
        if(now % 7 == 0) ans++;
    }

    cout << ans << endl;
    return 0;
}