#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 cost1 = 0;
	int cost2 = 100000;
	if (diffA <= diffB || S == 1) {
		cost1 = diffA + S;
	}
	else {
		cost1 = diffB + (S - 1) + abs(1 - A) + 1;
		if (A != 0) {
			cost2 = diffB + diffA + A;
		}
	}
	
	cout << min(cost1, cost2) << endl;




    return 0;
}