#include <bits/stdc++.h>
using namespace std;
int n;
int homes[200005];
bool can(long long d) {
  long long mxvis = 0, sta = 3;
  for (int i = 0; i < n; ++i) {
    if (homes[i] > mxvis) {
      if (sta < 1) return false;
      mxvis = homes[i] + 2 * d;
      --sta;
    }
  }
  return true;
}
long long bs() {
  long long lo = 0, hi = 2000000005, mid;
  while (lo < hi) {
    mid = (lo + hi) / 2;
    if (can(mid))
      hi = mid;
    else
      lo = mid + 1;
  }
  return lo;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) scanf("%d", homes + i), homes[i] *= 2;
  sort(homes, homes + n);
  long long d = bs();
  printf("%6f\n", (double)d / 2);
  int mxvis = 0, sta = 3;
  for (int i = 0; i < n; ++i) {
    if (homes[i] > mxvis && sta) {
      printf("%6f ", (double)(homes[i] + d) / 2), --sta,
          mxvis = homes[i] + 2 * d;
    }
  }
  while (sta) printf("%6f ", (double)homes[n - 1]), --sta;
  return 0;
}
