#include <iostream>
#include <cstdio>
#include <algorithm>

using namespace std;

int main() {
	int r, g, b;

	cin >> r >> g >> b;

	int ans = 0, tmp;
	for (int bit = 29; bit >= 0; bit--) {
		tmp = ans | (1 << bit);

		int plus  = max(0, (r - tmp) / 2) + max(0, (g - tmp) / 2) + max(0, (b - tmp) / 2);
		int minus = max(0, tmp - r) + max(0, tmp - g) + max(0, tmp - b);

		if (plus >= minus) {
			ans = tmp;
		}
	}

	cout << ans << endl;
	return 0;
}