CF478C 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

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.