import java.util.Arrays;
import java.util.Scanner;

public class Main {

	@SuppressWarnings("resource")
	public static void main(String args[]) {
		Scanner scanner = new Scanner(System.in);
		int r=scanner.nextInt();
		int b=scanner.nextInt();
		int g=scanner.nextInt();
		int x[]=new int[3];
		x[0]=r;
		x[1]=b;
		x[2]=g;
		Arrays.sort(x);
		while(true) {
		if(x[2]-x[0]<3)break;
		x[0]++;
		x[2]-=2;
		Arrays.sort(x);
		}
		System.out.println(x[0]);
	}
}