There are five volcanic islands E, F, G, H and I along the eastern coast of a country, which are arranged in a straight line from north to south. At the same time, it is found that: (1) F is adjacent to H and to the north of H. (2) I and E are adjacent. (3) G is somewhere to the north of F.
If G is found to be the northernmost island, the possible order of the group of islands is 4.