import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt(), y = sc.nextInt(), z = sc.nextInt();
        int ans = 0;
        for (int i = 0; i <= z; i++) {
            ans = Math.max(ans, Math.min(x+i, y+z-i));
        }
        System.out.println(ans);
    }
}