#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 ans = 0;
	
	while (true) {
		sort(cnt, cnt + 3);
		
		int x = min(cnt[1] - cnt[0], (cnt[2] - cnt[0]) / 3);
		cnt[0] += x;
		cnt[2] -= x * 2;
		
		sort(cnt, cnt + 3);
		int now = cnt[0];
		REP(i, 3) cnt[i] -= now;
		
		if (now == 0) break;
		
		ans += now;
	}
	
	cout << ans << endl;
	
	
	return 0;
}