#include<stdio.h>
#include<math.h>

int main(void){
	double x,y,r;
	int a;
	scanf("%lf%lf%lf",&x,&y,&r);
	x = sqrt(x*x)+sqrt(y*y);
	r = r*2/sqrt(2);
	x+=r;
	a = x;
	printf("%d\n",a+1);
}