#include <iostream>
using namespace std;
int main(int argc, char* argv[])
{
	int R,G,B;
	cin>>R>>G>>B;
	int ans=0;
	int Min=min(R,min(G,B));	
	int Max=max(R,max(G,B));
	int Mid=R+B+G-Min-Max;
	while (true){
		if (Max<=2 && Min==0){
			break;
		}
		while (Max>2){
			Max-=2;
			Min++;
			if (Max>2 && Mid==0){
				Max-=2;
				Mid++;
			}
			if (Mid>0 && Mid>0){
				break;
			}
		}
		ans+=Min;
		Max-=Min;
		Mid-=Min;
		Min=0;
		int Val=Max+Mid+Min;
		Max=max(Max,max(Mid,Min));
		Min=min(Max,min(Mid,Min));
		Mid=Val-Max-Min;
	}
	cout<<ans<<endl;
	return 0;
}