#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    
    int A,B,S;
    cin >> A >> B >> S;
    
    int ans = 0;
    if ( abs( S-A ) <= abs( S-B ) || S == 1 ) {
        ans = abs( S-A ) + S;
    }
    else {
        ans += abs( S-B );
        if ( A == 0 ) { A = 1; ans++; }        
        ans += min( abs(S-A)+A, S-1+A );
    }
    
    cout << ans << endl;
    
    return 0;
}