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 1\,000\,000\,000~

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.