package no091;

import java.util.Scanner;

public class Main {
	public static final int MAX = 10000000;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int r = sc.nextInt();
		int g = sc.nextInt();
		int b = sc.nextInt();
		for(int i=MAX;i>=0;i--) {
			int sum = r + g + b;
			int need = 0;
			need += r < i ? r + (i-r) * 2 : i;
			need += g < i ? g + (i-g) * 2 : i;
			need += b < i ? b + (i-b) * 2 : i;
			//System.out.println(i + "," + need);
			if (sum >= need) {
				System.out.println(i);
				break;
			}
		}
	}

}