#include <algorithm>
#include <cmath>
#include <deque>
#include <iostream>
#include <numeric>
#include <string>
#include <utility>
#include <vector>

using namespace std;
#define ALL(a) (a).begin(), (a).end()
#define FOR(i, n) for (size_t i = 0; i < (n); i++)
#define REP(n) FOR(i, n)
#define cinv(v, n) REP(n) {cin>>(v)[i];}
#define nvec(T, v, n) vector<T> v(n); cinv(v, n)
#define npairs(T1, T2, v, n) vector<pair<T1, T2>> v(n); REP(n){cin>>v[i].first>>v[i].second;}
#define ntuples(T1, T2, T3, v, n) vector<tuple<T1, T2, T3>> v(n); REP(n){cin>>get<0>(v[i])>>get<1>(v[i])>>get<2>(v[i]);}

#define min_index(v) size_t( min_element(all(v)) - (v).begin() )
#define max_index(v) size_t( max_element(all(v)) - (v).begin() )
#define min_e(v) *min_element(ALL(v))
#define max_e(v) *max_element(ALL(v))

#define count_le(v, a) size_t( upper_bound(ALL(v), a) - (v).begin() )
#define count_lt(v, a) size_t( lower_bound(ALL(v), a) - (v).begin() )
#define count_ge(v, a) size_t( (v).end() - lower_bound(ALL(v), a) )
#define count_gt(v, a) size_t( (v).end() - upper_bound(ALL(v), a) )

#define order(neq_sl) [](const auto s, const auto l){return neq_sl;}
#define make_lr(v,type,l,r) vector<type> l(n+1),r(n+1);FOR(i,n){l[i+1]=l[i]+v[i];r[i+1]=r[i]+v[n-1-i];}

#define acm accumulate
#define pub push_back
#define pof pop_front
#define SUM(v) accumulate(ALL(v), 0l)
#define SORT(v) sort(ALL(v))

#define GCD(v) gcd(ALL(v), 0l)

template <typename T>
T gcd(T a, T b) {
    if (a > b) swap(a, b);
    if (a == 0) return b;
    return gcd(b%a, a);
}
template <typename InputItr, typename T>
T gcd(InputItr first, InputItr last, T init) {
    for (; first != last; ++first) init = gcd(init, *first);
    return init;
}



int main(){
  long n;
  cin>>n;
  cout<<n*(n+1)/2-3*(n/3)*(n/3+1)/2-5*(n/5)*(n/5+1)/2+15*(n/15)*(n/15+1)/2;
}






/* きょむ〜 */