#include <bits/stdc++.h>
#include<iostream>
#include<iomanip>
#include<string>
#include<algorithm>
#include<vector>
#include<set>
#include<list>
#include<queue>
#include<math.h>
#include<bitset>
using ll = long long;
using namespace std;


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