The Great Run

Vishal loves running. He often visits his favourite Nehru Park and runs for very long distances. On one such visit he found that the number of girls in the park was unusually high. Now he wants to use this as an opportunity to impress a large number of girls with his awesome speed. The track on which he runs is an $\text{N}$ kilometres long straight path. There are $\mathbf{a_i}$ girls standing