import java.io.*;
import java.util.*;
 
public class Main{
	public void solve(){
		int A = nextInt();
		int B = nextInt();
		int S = nextInt();
		if(Math.abs(A - S) <= Math.abs(B - S)){
			out.println(Math.abs(A - S) + S);
		}else if(A == 0){
			out.println(Math.abs(B - S) + S - 1 + 2);
		}else{
			int a1 = Math.abs(B - S) + Math.abs(A - S) + A;
			int a2 = Math.abs(B - S) + S - 1 + A; 
			out.println(Math.min(a2, a1));
		}
	}
	
	public boolean check(String str, int idx){
		if(idx + 3 >= str.length()) return false;
		if(str.charAt(idx) != 'i') return false;
		if(str.charAt(idx + 1) != 'w') return false;
		if(str.charAt(idx + 2) != 'i') return false;
		return true;
	}
	
	private static PrintWriter out;
	public static void main(String[] args){
		out = new PrintWriter(System.out);
		new Main().solve();
		out.flush();
	}
	
	
	
	public static int nextInt(){
		int num = 0;
		String str = next();
		boolean minus = false;
		int i = 0;
		if(str.charAt(0) == '-'){
			minus = true;
			i++;
		}
		int len = str.length();
		for(;i < len; i++){
			char c = str.charAt(i);
			if(!('0' <= c && c <= '9')) throw new RuntimeException();
			num = num * 10 + (c - '0');
		}
		return minus ? -num : num;
	}
	
	public static long nextLong(){
		long num = 0;
		String str = next();
		boolean minus = false;
		int i = 0;
		if(str.charAt(0) == '-'){
			minus = true;
			i++;
		}
		int len = str.length();
		for(;i < len; i++){
			char c = str.charAt(i);
			if(!('0' <= c && c <= '9')) throw new RuntimeException();
			num = num * 10l + (c - '0');
		}
		return minus ? -num : num;
	}
	public static String next(){
		int c;
		while(!isAlNum(c = read())){}
		StringBuilder build = new StringBuilder();
		build.append((char)c);
		while(isAlNum(c = read())){
			build.append((char)c);
		}
		return build.toString();
	}
	
	
	private static byte[] inputBuffer = new byte[1024];
	private static int bufferLength = 0;
	private static int bufferIndex = 0;
	private static int read(){
		if(bufferLength < 0) throw new RuntimeException();
		if(bufferIndex >= bufferLength){
			try{
				bufferLength = System.in.read(inputBuffer);
				bufferIndex = 0;
			}catch(IOException e){
				throw new RuntimeException(e);
			}
			if(bufferLength <= 0) return (bufferLength = -1);
		}
		return inputBuffer[bufferIndex++];
	}
	
	private static boolean isAlNum(int c){
		return '!' <= c && c <= '~';
	}
}