#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000


int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	int A, B, S;
	cin >> A >> B >> S;
	int diffA = abs(S - A);
	int diffB = abs(S - B);
	int cost = 0;
	int cost2 = 10000;
	if (diffA > diffB && !(A == 0 && S == 1)) {
		cost += diffB;
		B = S;
		if (A != 0) {
			cost += diffA;
			B = A;
		}
		else {
			cost += diffA - 1;
			B = 1;
			cost += 2;
		}
		if (A == 0) A = 2;
		cost2 = diffB + S - 1 + A;
	}
	else {
		if (S == 1) {
			if (A == 0) A = 2;
			cost = A;
		}
		else {
			cost += diffA;
			A = S;
		}
	}
	
	cout << min(A + cost, cost2) << endl;




    return 0;
}