#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long ll;

const double EPS = 1e-8;
const int INF = 1e9;
const int MOD = 1e9+7;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

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

	if(abs(a-s) <= abs(b-s) || s == 1){
		cout << abs(a-s) + s << endl;
	}else{
		int ans = abs(s-b);
		
		//Aが地下にある可能性を考慮してない
		if(b > a){
			ans += s;
			if(a == 0){
				s += 1;
			}
		}else{
			int BtoA = abs(b-a);
			int Ato1 = a-1;
			int Bto1 = b-1;
			if(BtoA < Ato1){
				ans += BtoA + a;
			}else{
				ans += Bto1 + a;
			}

		}
		cout << ans << endl;
	}

	return 0;
}