#include <bits/stdc++.h>
using namespace std;
long long a[3];
int main() {
  scanf("%lld%lld%lld", &a[0], &a[1], &a[2]);
  sort(a, a + 3);
  printf("%lld\n", min(a[0] + a[1], (a[0] + a[1] + a[2]) / 3));
  return 0;
}
