#include<stdio.h>
#include<math.h>
int sei(int i){
  int ans = 1;
  if(i < 0){
    ans *= -1*i;
  }
  return ans;
}
int main(){
  short int x,y,r;
  scanf("%hd%hd%hd",&x, &y, &r);
  sei(x); sei(y);
  double root2;
  root2 = sqrt(2);
  double manhdis;
  manhdis = x+y+r*root2;
  int i = 0;
  while(i < manhdis){
    i++;
  }
  printf("%d",i);
  return 0;
}