#include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>

#define INF 1000000000

using namespace std;
typedef long long ll;

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