#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<29;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int main() {
	int cnt[3];
	REP(i, 3) cin >> cnt[i];
	
	int l = 0, r = 1e8;
	
	while (r - l > 1) {
		int m = (l + r) / 2;
		
		int add = 0, nec = 0;
		REP(i, 3) {
			if (cnt[i] >= m) add += (cnt[i] - m) / 2;
			else nec += m - cnt[i];
		}
		
		if (nec <= add) l = m;
		else r = m;
	}
	
	cout << l << endl;
	
	
	return 0;
}