A9573. Table Decorations

You have $r$ red, $g$ green and $b$ blue balloons. To decorate a single table for the banquet you need exactly three balloons. Three balloons attached to some table shouldn't have the same color. What maximum number $t$ of tables can be decorated if we know number of balloons of each color?

Your task is to write a program that for given values $r$ , $g$ and $b$ will find the maximum number $t$ of tables, that can be decorated in the required manner.

The single line contains three integers $r$ , $g$ and $b$ ( $0<=r,g,b<=2·10^{9}$ ) — the number of red, green and blue baloons respectively. The numbers are separated by exactly one space.

Print a single integer $t$ — the maximum number of tables that can be decorated in the required manner.

In the first sample you can decorate the tables with the following balloon sets: "rgg", "gbb", "brr", "rrg", where "r", "g" and "b" represent the red, green and blue balls, respectively.