// Enjoy your stay.

#include <bits/stdc++.h>

#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define ite iterator
#define mp make_pair
#define mt make_tuple
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define sec second
#define sz(x) ((int)(x).size())

using namespace std;

typedef istringstream iss;
typedef long long ll;
typedef pair<ll,ll> pi;
typedef stringstream sst;
typedef vector<ll> vi;



int main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);
	
	int a[3];
	cin>>a[0]>>a[1]>>a[2];
	for(int ans = 10000010; ans >= 0; ans--){
		int s = 0, o = 0;
		rep(i,3){
			s += max(0, ans - a[i]);
			o += max(0, (a[i] - ans) / 2);
		}
		if(s <= o) return cout<<ans<<endl,0;
	}
}