#include <iostream>
#include <stack>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>
#include <stdlib.h>
#include <math.h>


using namespace std;

/*
cin.ignore();
	getline(cin,dataStr);
	data = new int[n];
	stringToInteger(&dataStr,data,n);
*/

void stringToInteger(string *str,int *data,int n){
	for(int i=0;i<n;i++){
		int spaceN = str->find(' ',0);

		data[i] = atoi(str->substr(0,spaceN).c_str());
		str->erase(0,spaceN+1);
	}
}

void swap(int *a,int *b){
	int tmp = *a;
	*a = *b;
	*b = tmp;
}



void babbleSort(int *data,int n){
	for(int i=0;i<n;i++){
		for(int j=n-1;j>i;j--){
			if(data[j]>=data[j-1]){
				swap(&data[j],&data[j-1]);
			}
		}
	}
}



int main(){

	int data[3];
	cin>>data[0]>>data[1]>>data[2];

	//0:biggest 2:smallest
	babbleSort(data,3);

	int tmp = data[1]-data[2];

	if(data[0] - tmp*2 >= data[2]){
		data[0] -= tmp*2;
		data[2] += tmp;

		int tmp2 = (data[0]-data[2])/5;

		data[0] -= tmp2*4;
		data[1] += tmp2;
		data[2] += tmp2;
		if(data[0]<data[1]){
			data[0] += 4;
			data[1] -= 1;
			data[2] -= 1;
		}
	}



	else{
		tmp = data[0] - data[1];
		if(tmp%2 ==0){
			data[0] -= tmp;
			data[2] += tmp/2;
		}
		else{
			data[0] -= (tmp-1);
			data[2] += (tmp+1)/2;
		}

		int tmp2 = (data[0] - data[2])/4;

		data[0] -= tmp2*2;
		data[1] -= tmp2*2;
		data[2] += tmp2*2;

		babbleSort(data,3);
		while(1){
			if(data[0]>=data[2]+2){
				data[0] -= 2;
				data[2] += 1;
			}
			if(data[1]>=data[2]+2){
				data[1] -= 2;
				data[2] += 1;
			}

			if(data[0] <(data[2]+2) && data[1] <(data[2] + 2)) break;
		}

	}

	babbleSort(data,3);

	cout<<data[2]<<endl;

	return 0;

}