#include <algorithm>
#include <climits>
#include <cstdlib>
#include <vector>
#include <cctype>
#include <deque>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <ctime>
#include <stack>
#include <cstdio>
#include <string>
#include <iomanip>
#include <cstring>
#include <iostream>
#include <functional>

using namespace std;

typedef long long ll;


#define LLMAX LLONG_MAX
#define IMAX INT_MAX

int d(int x, int p) {
  return p < x ? p-x : (p-x)/2;
}

bool check(int x, int r, int g, int b) {
  return d(x,r)+d(x,g)+d(x,b) >= 0;
}

int main() {
  int r, g, b;
  cin >> r >> g >> b;
  int lo = 0, up = 10000000;
  for (int i = 0; i < 100; i++) {
    int cp = (lo+up)/2;
    if (check(cp, r, g, b)) {
      lo = cp;
    }else {
      up = cp;
    }
  }

  cout << lo << endl;
}