#include <algorithm>
#include <vector>
#include <cfloat>
#include <string>
#include <cmath>
#include <set>
#include <cstdlib>
#include <map>
#include <ctime>
#include <iomanip>
#include <functional>
#include <deque>
#include <iostream>
#include <cstring>
#include <queue>
#include <cstdio>
#include <stack>
#include <climits>
#include <sys/time.h>
#include <cctype>

using namespace std;

typedef long long ll;


int main() {
  int a, b, s;
  cin >> a >> b >> s;
  int sum = 0;
  if (abs(s-b) < abs(s-a)) {
    sum += abs(s-b);
    b = s;
    if (a == 0) {
      sum += (s-1)+2;
    }else {
      sum += min(abs(s-a)+a, (s-1)+a);
    }
  }else {
    sum += abs(s-a)+s;
  }
  std::cout << sum << std::endl;
}