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

void run(void){
  int x,y,r;
  scanf("%d%d%d",&x,&y,&r);

  x=abs(x);
  y=abs(y);

  int ans=x+y+1+(int)(sqrt(2)*r);
  printf("%d\n",ans);
  return;
}

int main(void){
  run();
  return 0;
}