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

#define PI 3.141592

int main(){
  int x, y, r;
  int m = 0;

  double deg = 45;
  double rad = deg * PI /18.0;

  scanf("%d%d%d",&x, &y, &r);

  m += abs(x) + abs(y) + ceil(r * sqrt(2));

  printf("%d\n",m);
  return 0;
}