#include<stdio.h>
#include<algorithm>
#include<math.h>
using namespace std;
int main(){
	int a,b,c;
	scanf("%d%d%d",&a,&b,&c);
	int A=a-b;
	if(A<0)A=-A;
	int B=a+b;
	if(B<0)B=-B;
	double s=max(A,B)+sqrt(2.0)*c;
	printf("%d\n",(int)s+1);
}