#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define pb push_back
#define INF 0x3f3f3f3
#define LINF 0x3f3f3f3f3f3f3f
#define MAXN int(2*1e5)+5
#define fim '\n'
#define ll long long
#define f first
#define s second
#define FAST cin.tie(0), cout.tie(0), ios::sync_with_stdio(0)
#define debug(x) cout << "DEBUG " << x << fim
#define debug2(x, y) cout << "DEBUG " << x << " " << y << fim
#define debug3(x, y, z) cout << "DEBUG " << x << " " << y << " " << z<< fim
#define debug4(x, y, z, o) cout << "DEBUG " << x << " " << y << " " << z<< " " << o << fim
#define max3(x, y, z) max(x, max(y, z))
#define ull unsigned long long
using namespace std;
using namespace __gnu_pbds;
typedef pair<int, int> pii;
typedef pair<string, int> psi;
typedef pair<unsigned ll, pair<int, int> > piii;
typedef pair<pair<int, int>, int> piii2;
typedef tree<int,null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> indexed_set;
const ll MOD = 1e9+7;

using namespace std;

int main() {
    int n;
    cin >> n;
    ll sum = 0;
    for(int i = 1; i <= n; i++)
        if(i%3 && i%5) sum += i;
    cout << sum << endl;
}