import java.util.*;

public class No091{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		int r = sc.nextInt();
		int g = sc.nextInt();
		int b = sc.nextInt();
		int[] rgb = new int[]{r, g, b};
		Arrays.sort(rgb);

		while(true){
			int[] rgb_new = new int[]{rgb[0]+1, rgb[1], rgb[2]-2};
			Arrays.sort(rgb_new);
			if(rgb_new[2]-rgb_new[0] <= 2){
				rgb = rgb_new;
				break;
			}else{
				rgb = rgb_new;
			}
			// System.out.println(Arrays.toString(rgb));
		}
		System.out.println(rgb[0]);
	}
}