Score : $200$ points
Some number of chocolate pieces were prepared for a training camp. The camp had $N$ participants and lasted for $D$ days. The $i$-th participant ($1 \leq i \leq N$) ate one chocolate piece on each of the following days in the camp: the $1$-st day, the $(A_i + 1)$-th day, the $(2A_i + 1)$-th day, and so on. As a result, there were $X$ chocolate pieces remaining at the end of the camp. During the camp, nobody except the participants ate chocolate pieces.
Find the number of chocolate pieces prepared at the beginning of the camp.
Input is given from Standard Input in the following format:
$N$ $D$ $X$ $A_1$ $A_2$ $:$ $A_N$
Find the number of chocolate pieces prepared at the beginning of the camp.
3 7 1 2 5 10
8
The camp has $3$ participants and lasts for $7$ days. Each participant eats chocolate pieces as follows:
Since the number of pieces remaining at the end of the camp is one, the number of pieces prepared at the beginning of the camp is $1 + 4 + 2 + 1 = 8$.
2 8 20 1 10
29
5 30 44 26 18 81 18 6
56