Some students are sitting in a row facing north. Their location depends on the following conditions: 1. B sits immediately adjacent to both G and
D. 2. H sits third to the left of
B. H sits second to the right of
A. 3. C sits immediately adjacent to both H and G. 4. A and F are sitting at the ends of the row, and F sits second to the right of
B. How many students are there in the row?