import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] rgbs = br.readLine().split(" ");
        int[] rgb = new int[3];
        for (int i = 0; i < 3; i++) {
            rgb[i] = Integer.parseInt(rgbs[i]);
        }
        while (true) {
            int avg = (rgb[0] + rgb[1] + rgb[2]) / 3;
            if (rgb[0] < avg + 2 && rgb[1] < avg + 2 && rgb[2] < avg + 2) {
                break;
            }
            for (int i = 0; i < 3; i++) {
                while (rgb[i] >= avg + 2) {
                    int min = Integer.MAX_VALUE;
                    int mini = 0;
                    for (int j = 0; j < 3; j++) {
                        if (j == i) continue;
                        if (min > rgb[j]) {
                            min = rgb[j];
                            mini = j;
                        }
                    }
                    rgb[mini]++;
                    rgb[i] -= 2;
                }
            }
        }
        System.out.println(Math.min(Math.min(rgb[0], rgb[1]), rgb[2]));
    }
}