/*An anomaly, I'm Muhammad Ali
  'Cause I know one day I'm gonna be the*/
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define llpow(a,b) (ll)(pow(a,b)+0.5)
#define f first
#define s second
const  int mod = 1000000007;
void add(ll& a, ll b){a+=b;while(a>=mod)a-=mod;while(a<0)a+=mod;}
void mul(ll& a, ll b){a*=b;while(a>=mod)a-=mod;while(a<0)a+=mod;}
ll binexpomodulo(ll x, ll y){ll res =1;x%=mod;if(!x)return 0;while(y){if(y&1){mul(res, x);}mul(x,x);y>>=1;}return res;}
ll nCrInOr(ll n, ll r){ll res = 1;if(r>n-r)r = n-r;ll rin = 1;for(ll i = 1; i <=r ; i++)rin = (rin*i)%mod;rin = binexpomodulo(rin,mod-2);for(ll i = 1; i <= r; i++)res = (res*(n-i+1))%mod;res = (res*rin)%mod;return res;}
int main()
{
	ll n; cin>>n;
	ll sum = 0;
	for(ll i  = 1 ; i <=n; i++)
		if(i%3&&i%5)
			sum+=i;
	cout<<sum<<endl;
  	return 0;
}