#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>

using namespace std;

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

	cin >> a >> b >> s;

	int ans = 0;
	if (a == 0) {
		a = 1;
		ans++;
	}

	if (s == 1) {
		ans += a;
	} else if (abs(a - s) <= abs(b - s)) {
		ans += abs(a - s) + s;
	} else {
		ans += abs(b - s) + min(abs(s - a) + a, s - 1 + a - 1 + 1);
	}
	cout << ans << endl;
	return 0;
}