Station Counter

There are $N+1$ stations in the city, numbered from $1$ to $N+1$. A train moves only in one direction starting from station $1$ to station $N+1$. The distance $D_i$ between the stations is given. A passenger on the train is trying to find the total combinations of stations such that the number of stations passed is equal to the distance covered by the train. Suppose there are $4$ stations, and