Sightseeing trip

The pupils from 10-B class decided in the autumn holiday to go on an excursion to the capital. Knowing the number of boys $n$ and girls $m$, determine how many rooms you need to book in a hotel, if each room has $k$ beds and it is forbidden to settle boys and girls together.

Input

One line contains three numbers $n,m,k(n,m,k\le 100)$.

Output

Print the number of rooms to book in the hotel.

Examples