#include <iostream>
#include <math.h>
using namespace std;

int main() {
	int a, b, s;
	cin >> a >> b >> s;

	int res;
	int a_to_s = abs(a - s);
	int b_to_s = abs(b - s);

	if (b_to_s < a_to_s && s != 1) {
		res = b_to_s + a;
		if (s - 1 < a_to_s) {
			if (a == 0) {
				res += s + 1;
			}
			else {
				res += s - 1;
			}
		}
		else {
			res += a_to_s;
		}
	}
	else {
		res = a_to_s + s;
	}

	cout << res << endl;

	return 0;
}