#include <bits/stdc++.h>
using namespace std;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#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(x) (x).begin(), (x).end()
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define RITR(x,c) for(__typeof(c.rbegin()) x=c.rbegin();x!=c.rend();x++)
#define BIT(n) (1LL<<(n))
#define SZ(x) ((int)(x).size())
typedef long long ll;
// -------------------------------------

int ma, mi, mu;

bool check(int x) {
  if (mi >= x) return true;
  else if (mu >= x) {
    int a = ma - x;
    int u = mu - x;
    return a / 2 + u / 2 + mi >= x;
  }
  else {
    int a = ma - x;
    a -= (x - mu) * 2;
    a -= (x - mi) * 2;
    return a >= 0;
  }
}

int main() {
  int R, G, B;
  cin >> R >> G >> B;

  ma = max({R, G, B});
  mi = min({R, G, B});
  mu = R + G + B - ma - mi;

  int ok = 0;
  int ng = ma + 1;

  while (abs(ok - ng) > 1) {
    int mid = (ok + ng) / 2;
    bool c = check(mid);
    //_P("%d, %d, %d -> %d\n", ok, ng, mid, c);
    if (c) ok = mid;
    else ng = mid;
  }

  cout << ok << endl;

  return 0;
}