#include <vector>
#include <string>
#include <algorithm>
#include <iostream>
#include <iomanip>
using namespace std;
int main(int argc, char * argv[])
{
vector<int> v(36000000);
int k = 0;
for(int i = 1; i <= 6000; ++i)
for(int j = 6001; j <= 12000; ++j)
v[k++] = i*j;
stable_sort(v.begin(),v.end());
long long s = 0;
for(int i = 0; i < 36000000; ++i) s += v[i];
cout << s;
}
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