#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;


int a, b, s;

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

	int move;

	if (s == 1) {
		move = abs(a - s) + s;
	} else if (abs(a - s) <= abs(b - s)) {
		move = abs(a - s) + s;
	} else {
		move = abs(b - s);

		if (a == 0) {
			move += s - 1 + 2;
		} else {
			move += min(a + s - 1, abs(a - s) + a);
		}
	}

	cout << move << endl;
	return 0;
}