#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<29;
const ll MOD = 1000000007;
const double EPS  = 1e-12;

int main() {
	int a, b, s;
	cin >> a >> b >> s;
	
	int ans;
	
	if (s == 1) {
		ans = a;
		if (ans == 0) ans = 2;
	}
	else if (abs(a - s) <= abs(b - s)) ans = abs(a - s) + s;
	else {
		ans = abs(b - s) + abs(s - a) + a;
		if (a == 0) chmin(ans, abs(b - s) + (s - 1) + 2);
		else chmin(ans, abs(b - s) + (s - 1) + a);
	}
	
	cout << ans << endl;
	
	return 0;
}