Information:  - Mali, officially the Republic of Mali, is a landlocked country in Africa. Mali is the eighth-largest country in Africa, with an area of just over . The population of Mali is 14.5 million. Its capital is Bamako. Mali consists of eight regions and its borders on the north reach deep into the middle of the Sahara Desert, while the country's southern part, where the majority of inhabitants live, features the Niger and Senegal rivers. The country's economy centers on agriculture and fishing. Some of Mali's prominent natural resources include gold, being the third largest producer of gold in the African continent, and salt. About half the population lives below the international poverty line of $1.25 (U.S.) a day. A majority of the population (90%) are Muslims.  - Grand Yoff is a commune d'arrondissement of the city of Dakar , Senegal . As of 2007 it had a population of 144,859 .  - Mauritania ('; or  Soninke: "Murutaane"; Pulaar: "Moritani"), officially the Islamic Republic of Mauritania, is a country in the Maghreb region of western Africa. It is the eleventh largest country in Africa and is bordered by the Atlantic Ocean to the west, Morocco and the remnants of Western Sahara in the north, Algeria in the northeast, Mali in the east and southeast, and Senegal in the southwest.  - Senegal, officially the Republic of Senegal, is a country in West Africa. Senegal is bordered by Mauritania in the north, Mali to the east, Guinea to the southeast, and Guinea-Bissau to the southwest. Senegal also borders The Gambia, a country occupying a narrow sliver of land along the banks of the Gambia River, which separates Senegal's southern region of Casamance from the rest of the country. Senegal also shares a maritime border with Cape Verde. Senegal's economic and political capital is Dakar. It is the westernmost country in the mainland of the Old World, or Afro-Eurasia, and owes its name to the Senegal River, which borders it to the east and north. The name "Senegal" comes from the Wolof "Sunuu Gaal", which means "Our Boat". Senegal covers a land area of almost and has an estimated population of about 13 million. The climate is Sahelian, but there is a rainy season.  - Dakar is the capital and largest city of Senegal.  - West Africa, also called Western Africa and the West of Africa, is the westernmost subregion of Africa. West Africa has been defined as including 18 countries: Benin, Burkina Faso, the island nation of Cape Verde, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, the island of Saint Helena, Senegal, Sierra Leone, São Tomé and Príncipe and Togo.  - Casamance is the area of Senegal south of the Gambia including the Casamance River. It consists of Basse Casamance ("Baixa Casamança", Lower Casamance i.e. Ziguinchor Region) and Haute Casamance ("Alta Casamança", Upper Casamance i.e. Kolda Region and Sédhiou Regions). The largest city of Casamance is Ziguinchor.  - The Gambia River (formerly known as the River Gambra) is a major river in West Africa, running from the Fouta Djallon plateau in north Guinea westward through Senegal and the Gambia to the Atlantic Ocean at the city of Banjul. It is navigable for about half that length.  - Guinea-Bissau, officially the Republic of Guinea-Bissau, is a country in West Africa. It covers with an estimated population of 1,704,000.  - Guinea , officially the Republic of Guinea, is a country on the West coast of Africa. Formerly known as French Guinea, the modern country is sometimes referred to as Guinea-Conakry in order to distinguish it from other parts of the wider region of the same name, such as Guinea-Bissau and Equatorial Guinea. Guinea has a population of 10.5 million and an area of .    What is the relationship between 'grand yoff' and 'banjul'?
A:
sister city