#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef set<int> si;
typedef map<string, int> msi;
#define REP(i,a,b) \
for(int i=int(a);i<=int(b);i++)
#define DEP(i,a,b) \
for(int i=int(a);i>=int(b);i--)
#define TRvi(c, it) \
for (vi::iterator it = (c).begin(); it != (c).end(); it++)
#define TRvii(c, it) \
for (vii::iterator it = (c).begin(); it != (c).end(); it++)
#define TRmsi(c, it) \
for (msi::iterator it = (c).begin(); it != (c).end(); it++)



int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	    ll n,i,j=0,k,l;
	    cin>>n;
	    REP(i,1,n){
	    	if(i%3!=0&&i%5!=0){
              j+=i;
	    	}
	    }
	    cout<<j;
	return 0;
}
