package no091;

import java.util.Arrays;
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[] m = new int[3];
		for(int i=0;i<3;i++) {
			m[i] = sc.nextInt();
		}
		int right = MAX+1;
		int left = 0;
		while(left + 1 < right) {
			int center = (right + left) / 2;
			int[] n = Arrays.copyOf(m, 3);
			int need = 0;
			for(int j=0;j<3;j++) {
				if (n[j] < center) {
					need += center - n[j];
					n[j] = 0;
				}else{
					n[j] -= center;
				}
			}
			//System.out.println(i + "," + need + "," + Arrays.toString(n));
			int amari = 0;
			for(int j=0;j<3;j++) {
				amari += n[j] / 2;
			}
			if (amari >= need) {
				left = center;
			}else{
				right = center;
			}
		}
		System.out.println(left);
	}

}