/*

*/
#include <bits/stdc++.h>
using namespace std;
#define pi acos(-1.0)
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define rep(i,a,n) for (ll i=a;i<n;i++)
#define per(i,a,n) for (ll i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((ll)(x).size())
#define cin1(x) cin >> x
#define cin2(x, y) cin >> x >> y
#define cin3(x, y, z) cin >> x >> y >> z
#define cou(x) cout << x
#define cous(x) cout << x << " "
#define coul(x) cout << x << "\n"
#define ret(x) return x
#define MAX 5000001
#define start int main() {   fastio
#define finish ret(0); }
#define minv(v) *min_element(v.begin(),v.end())
#define maxv(v) *max_element(v.begin(),v.end())
#define cntv(v,a) count(v.begin(),v.end(),a)
typedef long long ll;
typedef vector<ll> VI;
typedef pair<ll,ll> PII;
typedef double db;
//mt19937 mrand(random_device{}());
const ll mod=1000000007;
//ll rnd(ll x) { return mrand() % x;}
const ll X[]= {+0,+0,+1,-1,-1,+1,-1,+1};
const ll Y[]= {-1,+1,+0,+0,+1,+1,-1,-1};
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}ret(res);}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
ll fact[13];
void factorial() {   fact[0]=1;  rep(i, 1, 12) fact[i]=(fact[i-1]*i);  }
vector <ll> sie; //for sieve function
ll spf[MAX+7];  //for sieve function
void sieve() {    rep(i, 2, MAX)  {  if (spf[i] == 0) {  spf[i] = i;   sie.pb(i);  }    for (ll j=0; j<SZ(sie) && i*sie[j] <= MAX && sie[j] <= spf[i]; j++)   spf[i * sie[j]] = sie[j]; }   }
// head collected

ll t, n, k, _, __,ans;
string str;

start;

    cin1(t);

    ll sum = 0;
    rep(i, 1, t+1){
        if( i%3==0 || i%5==0)
            continue;
        sum += i;
    }


    coul(sum);
     /*if( a == 7 || b == 7 || c ==  7 )
        coul("Yes");
     else
        coul( "No");*/



finish
