Sudan, officially the Republic of the Sudan is an Arab republic in the Nile Valley of North Africa, bordered by Egypt to the north, the Red Sea, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the southwest, Chad to the west and Libya to the northwest. The Nile River divides the country into eastern and western halves. Its predominant religion is Islam. Almost one-fifth of Sudan's population lives below the international poverty line which means living on less than US$1.25 per day.Sudan was the largest country in Africa and the Arab world until 2011, when South Sudan separated into an independent country, following an independence referendum. Sudan is now the third largest country in Africa and also the third largest country in the Arab world.Sudan is a member of the United Nations, the African Union, the Arab League, the Organisation of Islamic Cooperation, and the Non-Aligned Movement; as well as an observer in the World Trade Organization. Its capital is Khartoum, the political, cultural and commercial centre of the nation. It is a federal presidential representative democratic republic. The politics of Sudan is regulated by a parliamentary organization called the National Assembly. The Sudanese legal system is based on Islamic law.Sudan suffers from several challenges, for much of Sudan's history the nation has suffered from rampant ethnic strife and has been plagued by internal conflicts including two civil wars and the War in the Darfur region. Sudan suffers from poor human rights most particularly dealing with the issues of ethnic cleansing and slavery in the nation.The Corruptions Perception Index, has indicated Sudan as one of the most corrupt nations in the world. According to the Global Hunger Index of 2013, Sudan has an GHI indicator value of 27.0 indicating that the nation has an 'Alarming Hunger Situation' and earning the nation the distinction of being the 5th hungriest nation in the world. According to the 2013 Human Development Index Sudan ranked the 171st place in Human Development, indicating Sudan still has one of the lowest human development in the world.