#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main() {
  int x,y,r;
  scanf("%d %d %d",&x,&y,&r);
  double l = fabs(x+y+sqrt(2)*r);
  printf("%d\n",(int)l+(l>(int)l?1:0));
  return 0;
}