package main

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

func solve(in io.Reader, out, err io.Writer) {
	x, y, r := 0.0, 0.0, 0.0
	fmt.Fscan(in, &x, &y, &r)
	fmt.Fprint(out, int(math.Ceil(math.Abs(x)+math.Abs(y)+math.Sqrt2*r)))
}

func main() {
	br := bufio.NewReaderSize(os.Stdin, int(1e2))
	solve(br, os.Stdout, os.Stderr)
}