The head of state is the queen of the United Kingdom, and the head of government is the prime minister of Canada. Canada is a vast and rugged land. From north to south, it spans more than half the Northern Hemisphere. Climates across Canada vary from region to region. Winters can be harsh in many parts of the country. It has over 40 million people. Canada ranks one of the best countries to live in, due to its multicultural background, safety, freedom, and high quality of life. Most of the population is living in the three largest cities: Toronto, Montreal, and Vancouver. Vancouver and Toronto are always ranked as the best cities to live in the world.