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

int main(void){
    
    int x,y,r;
    scanf("%d%d%d",&x,&y,&r);
    
    if(x<0)x=abs(x);
    if(y<0)y=abs(y);
    
    double X = x + r*0.70710678;
    double Y = y + r*0.70710678;
    
    if(X>=Y){
        double k=X;
        for(double j=Y;j>=0;j=j-0.1){
            k=k+0.1;  }
        printf("%d\n",(int)k+1);    }
    else if(X<Y){
        double k=Y;
        for(double j=X;j>=0;j=j-0.1){
            k=k+0.1;  }
        printf("%d\n",(int)k+1);   }
    
    
    return 0;
}