More complicated project

#include <QApplication>
#include <QHBoxLayout> //Helps you design widgets.
#include <QSlider>
#include <QSpinBox>

int main(int argc, char *argv[])
{
    QApplication prog(argc, argv);

    QWidget *mainWindow = new QWidget;
    mainWindow->setWindowTitle("How many chicken wings.");

    QSpinBox *spinner = new QSpinBox;
    QSlider *slider = new QSlider(Qt::Horizontal);

    spinner->setRange(1, 50);
    slider->setRange(1, 50);

    QObject::connect(spinner, SIGNAL(valueChanged(int)), slider, SLOT(setValue(int)));
    QObject::connect(slider, SIGNAL(valueChanged(int)), spinner, SLOT(setValue(int)));

    spinner->setValue(10);

    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(slider);
    layout->addWidget(spinner);
    mainWindow->setLayout(layout);
    mainWindow->show();

    return prog.exec();
}