#include <cstdio>
#include <cstring>
#include <cmath>
#include <climits>
#include <iostream>
#include <iomanip>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <algorithm>
#include <numeric>
#include <functional>

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define ALL(a) (a).begin(),(a).end()

using namespace std;
typedef long long ll;

int R, G, B;

bool ok(int n) {
  int shortage, surplus;
  shortage = max(0, n-R) + max(0, n-G) + max(0, n-B);
  surplus = max(R-n, 0) / 2 + max(G-n, 0) / 2 + max(B-n, 0) / 2;
  return surplus >= shortage;
}

int main(int argc, char *argv[])
{
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> R >> G >> B;
  int ret = 0;
  for (int i = 24; i >= 0; i--)
    if (ok(ret + (1<<i)))
      ret += 1<<i;
  cout << ret << endl;
  
  return 0;
}