#include <bits/stdc++.h>
using namespace std;
long long int factorial[10000001] = {0};
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long int powerFunction(long long int x, long long int y) {
  long long int res = 1;
  long long int p = 1000000007;
  x = x;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
void factorialFunction(long long int maxLimit) {
  factorial[0] = 1;
  for (long long int i = 1; i <= maxLimit; i++)
    factorial[i] = (factorial[i - 1] * i) % 1000000007;
  return;
}
long long int nCr(long long int n, long long int r) {
  if (r < 0 || r > n) {
    return 0;
  }
  long long int temp = factorial[n];
  temp *= (powerFunction(factorial[r], 1000000007 - 2) % 1000000007);
  temp %= 1000000007;
  temp *= (powerFunction(factorial[n - r], 1000000007 - 2) % 1000000007);
  temp %= 1000000007;
  return temp;
}
signed main() {
  vector<long long int> v(3);
  cin >> v[0] >> v[1] >> v[2];
  sort(v.begin(), v.end());
  if (v[2] >= 2 * (v[0] + v[1]))
    cout << v[0] + v[1] << "\n";
  else
    cout << (v[0] + v[1] + v[2]) / 3 << "\n";
}
