#include <iostream>
#include <vector>
#include <numeric>
using namespace std;
int main()
{
vector<double> coordinates;
coordinates.push_back(0.5);
coordinates.push_back(0.5);
coordinates.push_back(0.5);
cout<<inner_product(coordinates.begin(), coordinates.end(), coordinates.begin(), 0.0)<<endl;
return 0;
}
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