#include <bits/stdc++.h>
using namespace std;
#define REP(i, n)           for(int(i)=0;(i)<(n);++(i))

int zeller(long long year, int mon, int day){
    if(year < 1582 || mon < 1 || day < 1) throw;
    if(mon <= 2){ year--; mon += 12; }
    unsigned int h = (year + year/4 - year/100 + year/400 + (13*mon+8)/5 + day) % 7;
    return h;
}

int main(){
    long long N;
    cin >> N;

    int c = 0;
    for(long long i = 2015; i <= min(2399LL,N); i++){
        if(zeller(i,7,23) == 3) c++;
    }
    if(N >= 2400){
        long long k = (N-2400)/400;
        c += 57*k;
        for(long long i = 2400+k*400; i <= N; i++){
            if(zeller(i,7,23) == 3) c++;
        }
    }
    cout << c << endl;
    return 0;
}