/**

author:	©LoneWolfDON
Git: MahinHossainMunna

**/
/*

*/
#include <stdio.h>
int main()
{
    int n;
    scanf("%d",&n);

    long long ans=0;

    for(int i=1;i<=n;i++)
    {
        if(i%3!=0 && i%5!=0)
            ans+=i;
    }
    printf("%lld\n",ans);

    return 0;
}

