#include using namespace std; typedef pair PII; typedef long long LL; typedef unsigned long long ULL; template inline bool amax (T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template inline bool amin (T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; } template ostream& operator << (ostream &os, const vector &v) { os << "["; for (typename vector::const_iterator it = v.begin(); it != v.end(); it++) { os << (it != v.begin() ? ", " : "") << *it; } os << "]"; return os; } template ostream& operator << (ostream &os, const set &s) { os << "["; for (typename set::const_iterator it = s.begin(); it != s.end(); it++) { os << (it != s.begin() ? ", " : "") << *it; } os << "]"; return os; } template ostream& operator << (ostream &os, const map &m) { os << "{"; for (typename map::const_iterator it = m.begin(); it != m.end(); it++) { os << (it != m.begin() ? ", " : "") << it->first << ":" << it->second; } os << "}"; return os; } template ostream& operator << (ostream &os, const pair &p) { os << "(" << p.first << ", " << p.second << ")"; return os; } template inline Target lexical_cast (const Source &s) { Target t; stringstream ss; ss << s; ss >> t; return t; } //> v < ^ (clock wise) int dx[] = {1,0,-1,0}; int dy[] = {0,1,0,-1}; const int INFI = 1<<28; const long long int INFL = 1LL<<60; const double INFD = 1e+300; const float INFF = 1e+100; const double EPS = 1e-8; bool leap (LL n) { return n % 4 == 0 && (n % 100 != 0 || n % 400 == 0); } int main(){ cout.setf(ios::fixed); cout.precision(10); ios_base::sync_with_stdio(false); LL n; cin >> n; LL d = 365 % 7; LL same = 0; for (LL i = 2015; i <= 2014+400; i++) { if (d == 0) { same++; } d += 365 + leap(i); d %= 7; } LL ans = (n - 2014) / 400 * same; d = 365 % 7; for (LL i = 2014+(n-2014)/400*400; i < n; i++) { if (d == 0) { ans++; } d += 365 + leap(i); d %= 7; } cout << ans << endl; return 0; }