package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)
var rdr = bufio.NewReaderSize(os.Stdin, 1000000)

func main() {
	sc.Split(bufio.ScanWords)
	a, b, s := nextFloat(), nextFloat(), nextFloat()

	if s == 1 {
		fmt.Println(int(math.Abs(a-s) + s))
		return
	}

	if math.Abs(a-s) <= math.Abs(b-s) {
		fmt.Println(int(math.Abs(a-s) + s))
		return
	}

	r1 := s - 1 + a + math.Abs(b-s)
	r2 := math.Abs(a-s) + a + math.Abs(b-s)
	if a == 0 {
		r1 += 2
		r2++
	}

	if r1 < r2 {
		fmt.Println(int(r1))
		return
	}
	fmt.Println(int(r2))
}

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	i, _ := strconv.Atoi(nextLine())
	return i
}

func nextFloat() float64 {
	f, _ := strconv.ParseFloat(nextLine(), 64)
	return f
}