package main

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

var s = bufio.NewScanner(os.Stdin)

func next() string {

	s.Scan()
	return s.Text()
}

func nextInt() int {
	i, e := strconv.Atoi(next())
	if e != nil {
		panic(e)
	}
	return i
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}


func main() {
	s.Split(bufio.ScanWords)
	x := nextInt()
	y := nextInt()
	r := nextInt()


	tmp := (float64(abs(x) + abs(y)) + float64(r) * math.Sqrt2)
	fmt.Println(math.Ceil(tmp))

}