#include <iostream>
#include <cassert>
#include <algorithm>

using namespace std;

bool possible(const int c[], int x) {
	int generated = 0;
	for (int i = 0; i < 3; ++i) {
		generated += max(0, c[i] - x) / 2;
	}
	for (int i = 0; i < 3; ++i) {
		if (c[i] < x) {
			generated -= x - c[i];
		}
	}
	return (generated >= 0);
}

int main() {
	int c[3];
	cin >> c[0] >> c[1] >> c[2];
	sort(c, c + 3);
	int low = c[0];
	int high = c[2] + 1;
	// x(possible(c,x)==true) is included in [low, high)
	while (low + 1 < high) {
		assert(possible(c, low));
		assert(!possible(c, high));
		int middle = (low + high) / 2;
		if (possible(c, middle)) {
			low = middle;
		} else {
			high = middle;
		}
	}
	cout << low << endl;
	return 0;
}