#include<bits/stdc++.h>
using namespace std;

struct ca
{
  int idx,st,et,aidx;
};

int prime[1000001]={};

int power(int x, unsigned int y, int p)  
{  
    int res = 1;     
  
    x = x % p; 
   
    if (x == 0) return 0; 
  
    while (y > 0)  
    {  
         
        if (y & 1)  
            res = (res*x) % p;  
  
        
        y = y>>1; 
        x = (x*x) % p;  
    }  
    return res;  
}  

void pr()
{
  prime[1]=0;

 for(int i=2;i*i<1000001;i++)
  if(prime[i]==0)
  for(int j=i*i;j<1000001;j+=i)
  prime[j]=1;

}

int countSetBits( int n) 
{ 
     int count = 0; 
    while (n) { 
        count += n & 1; 
        n >>= 1; 
    } 
    return count; 
} 
  
bool cmp1(ca c1,ca c2)
{
  if(c1.st<c2.st)
   return true;

  if(c1.st==c2.st && c1.idx<c2.idx)
   return true;

  return false;
}

bool cmp2(ca c1,ca c2)
{
  
  if(c1.idx<c2.idx)
  return true;
  return false;
}








int main()
{

    ios_base::sync_with_stdio(false); 
    cin.tie(NULL);  
   //pr();
  int t;
   //cin>>t;
   t=1;
  int id=1;

  while(t--)
{
   int n;
    cin>>n;
   
    long sum=0;
   int count=0;

  for(int i=1;i<=n;i++)
   if(i%3!=0 && i%5!=0)
   {
     sum+= i;
     count++;
   }

  cout<<sum;
}



return 0;
}
