#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>

//#include<bits/stdc++.h>


using namespace std;



int main() {
	
	int a, b, s;
	cin >> a >> b >> s;

	int x = 0, y = 0;

	if (abs(s - a) <= abs(s - b)) {
		x = abs(s - a);
		x += s;
	}
	else {
		x = abs(s - b);
		b = min(s, b);
		if (a!=1) {
			 x+=abs(a-1);
			 a = 1;
			 x += b - 1;
		}
		
		x += a;
	}

	cout << x << endl;

	return 0;


		
}