#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <stack>
#include <functional>
#include <complex>
#include <cmath>
#include <ccomplex>
using namespace std;

int sum(vector<int> v) {
	int sum = 0;
	for (int i = 0; i < 3; i++) {
		sum += v[i];
	}
	return sum;
}

bool check(vector<int> v) {
	bool ok = true;
	for (int i = 0; i < 3; i++) {
		if (v[i] < 0)ok = false;
	}
	return ok;
}
int main() {
	vector<int> color(3);
	for (int i = 0; i < 3; i++)cin >> color[i];

	int mn = *min_element(color.begin(), color.end());
	for (int i = 0; i < 3; i++)color[i] -= mn;
	int cnt = mn;
	sort(color.begin(), color.end());
	
	bool ok = true;
	while (ok) {
		if (sum(color) <= 2) {
			ok = false;
			break;
		}
		
		color[2] -= 2;
		color[0] += 1;
		ok = check(color);

		int mn = *min_element(color.begin(), color.end());
		if (mn >= 1) {
			cnt += mn;
			for (int i = 0; i < 3; i++)color[i] -= mn;
		}
		sort(color.begin(), color.end());
		cerr << color[0] << " " << color[1] << " " << color[2] << " " << cnt << endl;
	}
	cout << cnt << endl;
}