9 530792195 6
 0 0 10
 1944219055 454183506 1369298327
 914835 2742837 9234739
 10 10 0
 2 2 0
 0 0 1
 3 10 1007169359
 0 1 0
 1016450951 2 9
 0 2 10
 2147483648 0 2147483647
 92134834 23742837 92374738
 1 4 3
 382601556 881329640 791556039
 0 0 58
 5 10 6
 10 6 8
 6 8 10
 3 2 0
 1 4 4
 2147483630 2147483642 2147483610
 1 0 0
 18 67 5
 50606342 2 1134945035
 8 97 83
 2147483648 0 0
 92134834 23742837 92374737
 5 0 5
 772486757 1747374885 377299255
 1 0 1
 1 2 3
 0 3 2
 2147483648 2147483647 2147483648
 51 10 91
 9214834 2742837 9234739
 1 2 2147483648
 67 81 1
 92134834 23742837 92374739
 2 7 95
 3 0 2
 5 9 0
 1 10 2
 246543403 71853598 1504509195
 2147483648 2147483648 2147483648
 48 6 7
 2147483648 2147483648 0
 1358352906 27037371 1947040615

                                                       530792195
                                                                0
                                                       1944219055
                                                          2742837
                                                               10
                                                                2
                                                                0
                                                       1007169359
                                                                0
                                                       1016450951
                                                                2
 2147483648                                                         92374738
                                                                3
                                                        881329640
                                                                0
                                                               10
                                                                8
                                                                8
                                                                2
                                                                4
                                                       2147483630
                                                                0
                                                               67
                                                         50606342
                                                               97
                                                                0
                                                         92374737
                                                                5
                                                        772486757
                                                                1
                                                                3
                                                                2
 2147483648                                                               91
                                                          9234739
 2147483648                                                               67
                                                         92374739
                                                               95
                                                                2
                                                                9
                                                               10
                                                       1504509195
 2147483648                                                               48
 2147483648                                                       1947040615

#include <bits/stdc++.h>
using namespace std;
const int inf = 1000000000;
const int MOD = 1000000007;
int main() {
  long long b[3];
  cin >> b[0] >> b[1] >> b[2];
  sort(b, b + 2);
  long long ANS = inf * (long long)inf;
  do {
    long long a[3];
    a[0] = b[0], a[1] = b[1], a[2] = b[2];
    long long ans = 0;
    for (;;) {
      if (a[0] > a[1]) swap(a[0], a[1]);
      if (a[0] == 0 && a[1] == 0 || a[0] == 0 && a[2] == 0) break;
      if (a[0] == 0 && a[1] == 1) {
        ans += a[2];
        break;
      }
      long long t = min(a[0], a[1]);
      if (t) {
        ans += t;
        a[0] -= t;
        a[1] -= t;
        a[2] += t;
      } else {
        long long k = min(a[1] / 2, a[2]);
        ans += k;
        a[0] += k;
        a[1] -= k;
        a[2] -= k;
      }
    }
    ANS = min(ANS, ans);
  } while (next_permutation(b, b + 2));
  cout << ANS << endl;
}
