#include <vector>
#include <string>
#include <algorithm>
#include <iostream>
#include <iomanip>

using namespace std;

int main(int argc, char * argv[])
{
    vector<int> v;
    v.reserve(36000000);
    for(int i = 1; i <= 6000; ++i)
        for(int j = 6001; j <= 12000; ++j)
            v.push_back(i*j);
    sort(v.begin(),v.end());
    long long s = 0;
    for(int x: v) s += x;
    cout << s;
}