Roger is ordering pizza for DMPG. He knows that there are $P$ people who want to eat pepperoni pizza, $C$ people who want to eat cheese pizza, and $V$ people who want vegetarian pizza. If a single pizza feeds $3$ people, how many pizzas will Roger have to order?

Constraints

$0\le P,C,V\le 1000000000$

Input Specification

The first line will contain three space separated integers, $P$, $C$, and $V$.

Output Specification

A single integer, the total number of pizzas Roger has to order.

Sample Input

6 7 8

Sample Output

8

Explanation for Sample Output

Roger has to order 2 pepperoni pizzas, 3 cheese, and 3 vegetarian pizzas.