#include<stdio.h>
int main()
{
	int x, y, r;
	scanf("%d %d %d", &x, &y, &r);
	if (x < 0)
		x *= -1;
	if (y < 0)
		y *= -1;
	int ans = 0;
	while (ans <= (int)(r * 1.41421356))
		ans++;
	printf("%d\n", ans + x + y);
	return 0;
}