import java.math.*;
import java.util.*;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		
		if(Math.abs(a-c)<=Math.abs(b-c)||c==1){
			System.out.println(Math.abs(a-c)+Math.abs(c));
		}else{
			if(a!=0)System.out.println(Math.min(Math.abs(b-c)+(c-1)+a, Math.abs(b-c)+Math.abs(a-c)+a));
			else System.out.println(Math.abs(b-c)+(c-1)+2);
		}
	}
}