Opening many windows and drawing to them

Windows.cpp

#include <SFML/Graphics.hpp>
#include <iostream>

unsigned int first = 0;
unsigned int second = 0;
std::size_t count = 50;

void run()
{
    sf::CircleShape circle{10.f};
    sf::RectangleShape rectangle{{60.f, 20.f }};
    sf::RenderWindow window({800, 600}, "Minimal Example");
    int x = 1;

    while (x <= 2)
    {
        sf::Clock clock;

        // Start timing
        sf::Time startTime = clock.restart();

        // "Clear" the window from previouly drawn graphics
        window.clear(sf::Color::Black);
        window.draw(circle);
        window.draw(rectangle);
        window.display();

        // End timing
        sf::Time endTime = clock.restart();
        std::cout << x << ": " << endTime.asMicroseconds() << std::endl;

        if(x == 1)
            first += endTime.asMicroseconds();
        else if(x == 2)
            second += endTime.asMicroseconds();

        ++x;
    }
}

int main()
{
    for(std::size_t i = 0; i < count; ++i)
        run();

    std::cout << "1: " << static_cast<float>(first) / count << std::endl;
    std::cout << "2: " << static_cast<float>(second) / count << std::endl;
}