#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <tuple>
#define mkp make_pair
#define mkt make_tuple
#define rep(i,n) for(int i = 0; i < (n); ++i)
using namespace std;
typedef long long ll;
const ll MOD=1e9+7;

int main(){
  int X,Y,Z;
  cin>>X>>Y>>Z;

  int ans=0;
  if(X>Y) swap(X,Y);
  ans+=X;
  Y-=X;
  X=0;
  if(Z<=Y) ans+=Z;
  else ans+=Y+(Z-Y)/2;
  cout<<ans<<endl;

  return 0;
}