import java.util.Scanner;
class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt(),b = sc.nextInt(),s = sc.nextInt(),count = 0;
		if(Math.abs(a - s) <= Math.abs(b - s) || s == 1) {
			count += Math.abs(a - s) + s;
		}else {
			count += Math.abs(b - s);
			if(Math.abs(s - a) + a > (s - 1) + a) {
				count += s - 1 + a;
				if(a == 0)count += 2;
			}else {
				count += Math.abs(s - a) + a;
			}
		}
		System.out.println(count);
	}
}