package main

import (
	"fmt"
	"math"
)

func main() {
	var x, y, r int
	n := 0
	fmt.Scanf("%d %d %d", &x, &y, &r)

	r2 := float64(r) * math.Sqrt(2) / 2.0
	sign := []int{-1, 1}

	for _,sx := range sign {
		var px, py float64
		for _,sy := range sign {
			px = float64(x) + (float64(sx) * r2)
			py = float64(y) + (float64(sy) * r2)

			//fmt.Println("[sign] (", sx, ",", sy, ")")
			//fmt.Println("(", px, ", ", py, ")")
			//fmt.Println("md =", math.Abs(px)+math.Abs(py))

			if vd := math.Abs(px)+math.Abs(py); float64(n) < vd {
				n = int(math.Ceil(vd))
			}
		}
	}

	fmt.Println(n)
}