Number of Multiples

// computing number of multiples common from 3 and 5
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    long long n;
    cin>>n;
    long long count=0;
    long long count_3=(n)/3;
    long long count_5=(n)/5;
    long long count_15=(n)/15;
    count=count_3+count_5-count_15;
    cout<<count;
    return 0;
}