import java.util.Scanner;
public class Solution {
    public static void main(String[] args) throws Exception {
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        int c = scanner.nextInt();
        if (a == b && b == c){
            System.out.println(a);
        }else if (a==b){
            System.out.println(a);
        } else if (b == c){
            System.out.println(b);
        }else if (a == c){
            System.out.println(a);
        }
        else {
            System.out.println((a+b+c)/3);
        }

    }
}