A9158. Ciel and Flowers

Fox Ciel has some flowers: $r$ red flowers, $g$ green flowers and $b$ blue flowers. She wants to use these flowers to make several bouquets. There are 4 types of bouquets:

- To make a "red bouquet", it needs 3 red flowers.
- To make a "green bouquet", it needs 3 green flowers.
- To make a "blue bouquet", it needs 3 blue flowers.
- To make a "mixing bouquet", it needs 1 red, 1 green and 1 blue flower.

Help Fox Ciel to find the maximal number of bouquets she can make.

The first line contains three integers $r$ , $g$ and $b$ ( $0<=r,g,b<=10^{9}$ ) — the number of red, green and blue flowers.

Print the maximal number of bouquets Fox Ciel can make.

In test case 1, we can make 1 red bouquet, 2 green bouquets and 3 blue bouquets.

In test case 2, we can make 1 red, 1 green, 1 blue and 1 mixing bouquet.